CN113896338A

CN113896338A - Seawater pretreatment equipment used in seawater desalination and control method

Info

Publication number: CN113896338A
Application number: CN202110668808.7A
Authority: CN
Inventors: 张英华
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-06-04
Filing date: 2021-06-04
Publication date: 2022-01-07

Abstract

The invention discloses a seawater pretreatment device used in seawater desalination and a control method. The seawater pretreatment equipment consists of a stainless steel rotary net silt screening machine, a rotary net tank or a rotary ceramic tank, an algae centrifugal separator and a polymer centrifugal separator or a foamed ceramic evaporator, and is controlled by a computer controller. The dirty seawater pump pumps dirty seawater in the sea to the stainless steel rotary screen silt screening machine to screen silt. The seawater pump pumps the seawater from which the silt is removed to a rotary net tank or a rotary ceramic tank, and the seawater containing a large amount of algae enters an algae centrifugal separator to be dried and then is put into an algae pond. The micromolecule organic matter is compatible with the polymer purifying agent, is filtered out from the rotary screen tank, is sent into a polymer centrifugal separator for spin-drying to remove the micromolecule organic matter, and is then put into a polymer pool, or is extruded out from the rotary ceramic tank to a foamed ceramic evaporation pipe, seawater is extruded out, the micromolecule organic matter compatible with the polymer purifying agent is heated and evaporated, and the regenerated polymer purifying agent is sent back for reuse.

Description

Seawater pretreatment equipment used in seawater desalination and control method

The technical field is as follows:

the invention relates to seawater pretreatment equipment used in seawater desalination and a control method.

Background art:

at present, semipermeable membranes used for reverse osmosis seawater desalination are polyacrylamide non-woven fabrics and surface graphene oxide films. The surface graphene oxide film is too expensive to be popularized. After the seawater is subjected to sand filtration and algae removal, micromolecular organic matters and salts are left in the seawater. The size of the small molecular organic matter dissolved in water is similar to that of the salt molecules dissolved in water, so that the small molecular organic matter and the salt cannot be distinguished through filtration. The high pressure reverse osmosis method can only be used for filtering out small molecular organic matters and salts by using a semipermeable membrane. The brackish water is treated in northwest areas of China, and salt molecules can be driven away from the semipermeable membrane only by adding low-voltage direct current to an oil filling pipe between the semipermeable membrane and the shell; drinking water can then be produced by reverse osmosis using very low water pressures. The reverse osmosis seawater desalination membrane core using the polyacrylamide non-woven fabric semipermeable membrane has the highest efficiency when the temperature of seawater exceeds 20 ℃, firstly, the booster pump is used for pressurizing the seawater to 8 kilograms of pressure, water molecules in the seawater penetrate through the semipermeable membrane, the semipermeable membrane is gradually blocked along with time, and the squeezed fresh water is less and less; a pressure of 18 kg is required to allow more water molecules to pass through the semi-permeable membrane. When the semipermeable membrane is blocked to a certain degree, one energy recovery back washing is needed. After several times of energy recovery back flushing, back flushing is carried out for one time: after the concentrated seawater in the reverse osmosis membrane core is discharged, the high-pressure air blown out by a roots blower is used for back flushing the shift membrane. The main substance for blocking the semipermeable membrane is micromolecular organic matter, so after blowback for a plurality of times, the semipermeable membrane is cleaned once by strong acid medicine. The strong acid medicine and the micromolecular organic matter blocking the semipermeable membrane are subjected to chemical reaction, and the micromolecular organic matter is washed by the gear after being decomposed into inorganic matter. However, the strong acid medicament corrodes the polyacrylamide non-woven fabric semipermeable membrane severely, and after the polyacrylamide non-woven fabric semipermeable membrane is washed for a plurality of times by the strong acid medicament, the polyacrylamide non-woven fabric semipermeable membrane is corroded and discarded. The viscosity of the seawater solution of the small molecular organic matters is the lowest at the temperature of 20 ℃. Experiments of a research institute for seawater desalination of Qingdao Shandong, the inventor finds that when the seawater is at 20 ℃, the booster pump is firstly used for pressurizing the seawater to 8 kilograms of pressure, water molecules in the seawater penetrate through the semipermeable membrane, and the semipermeable membrane is gradually blocked along with the time, so that the squeezed fresh water is less and less; a pressure of 18 kg is required to allow more water molecules to pass through the semi-permeable membrane. When the seawater is at 0 ℃, firstly, a high-pressure pump is used for pressurizing the seawater to 18 kg of pressure, water molecules in the seawater penetrate through the semipermeable membrane, the semipermeable membrane is gradually blocked along with time, and the squeezed fresh water is less and less; a water pressure of 28 kg is required to allow more water molecules to pass through the semi-permeable membrane. The reason is that the viscosity of seawater solution of small molecular organic substances is very high at 0 ℃. If the small molecular organic matters in the seawater are removed, the viscosity of the seawater is the same at 0 ℃ and 20 ℃, so that the efficiency of reverse osmosis seawater desalination is high in both winter and summer.

The past domestic sewage treatment method is to collect the domestic sewage in an oxygen explosion pool, and then put some medicines into the oxygen explosion pool; organic matters in the domestic sewage are oxidized and decomposed into inorganic matters in the oxygen explosion pool to become reclaimed water, and the reclaimed water is discharged to the sea. The existing domestic sewage treatment method is to put resin purifying agent into the sand well and install a filter screen at the outlet of the sand well, so that the particles of the resin are very large, the meshes of the filter screen are also very large, and the phenomenon of sand well filter screen blockage can not occur. Organic matters in the domestic sewage are adsorbed by the resin purifying agent, and are decomposed into inorganic matters to be separated from the resin purifying agent after a period of time, and the resin purifying agent is stable and cannot be decomposed, so that the service life of the resin purifying agent is long, and the resin purifying agent can be used for a long period of time by adding the resin purifying agent once.

The invention content is as follows:

a seawater pretreatment device used in seawater desalination. The seawater pretreatment equipment consists of a stainless steel rotary net silt screening machine, a rotary net tank, an algae centrifugal separator, a polymer centrifugal separator and a delivery pump, and is controlled by a computer controller. The stainless steel rotary screen silt screening machine is made of a rotary shell, a stainless steel rotary screen, a gear reduction motor and a rotary support frame. The front part of the rotary shell is obliquely arranged on the front rotary support frame and the rear rotary support frame, the front annular rail is arranged at the position close to the front end of the stainless steel rotary net, and three front rollers arranged at the front section in the rotary shell are pressed on the front annular rail. The rear ring rail is arranged at the position close to the rear end of the stainless steel rotary net, and three rear rollers arranged at the rear section in the rotary shell are pressed on the rear ring rail. The gear reduction motor is arranged on the front rotary support frame, a ring gear is arranged at a position close to the front ring track of the stainless steel rotary net, and an output gear of the gear reduction motor is meshed with the ring gear arranged on the stainless steel rotary net. An annular baffle plate is arranged in the rotary shell close to the rear end of the stainless steel rotary net, a seawater pipe is arranged at the bottom of the rotary shell in front of the annular baffle plate, and an outlet of the seawater pipe is arranged above the seawater pool. A silt pool is arranged below the rear end of the rotary shell, and dirty seawater is pumped to the front end of the stainless steel rotary net from the sea by a dirty seawater pump. The rotary mesh tank consists of a mesh tank shell, a mesh tank sealing cover, a mesh tank sealing bottom, an outer stainless steel mesh clamp filter cloth pipe, an inner stainless steel mesh clamp filter cloth pipe, a mesh tank frame, a mesh tank central shaft, a mesh tank supporting frame and a mesh tank motor. The net tank shell is internally provided with a net tank frame, the net tank frame is sequentially provided with an outer stainless steel net clamp filter cloth pipe, an inner stainless steel net clamp filter cloth pipe and a net tank central shaft from outside to inside, the upper end of the net tank central shaft penetrates through a central bearing of a net tank sealing cover and then is connected with a rotating shaft of a net tank motor through a coupler, and the lower end of the net tank central shaft penetrates through a central bearing of a net tank sealing bottom. The net tank shell, the net tank sealing cover, the net tank sealing bottom and the net tank motor are fixed on the net tank frame supporting frame. The inner side of the outer stainless steel mesh clamp filter cloth pipe is provided with a plurality of turbine blades, and the inner side of the inner stainless steel mesh clamp filter cloth pipe is provided with a plurality of turbine blades. A seawater inlet pipe is arranged on a mesh tank sealing cover between the mesh tank shell and the outer stainless steel mesh clamp filtering cloth pipe, and a seawater electric butterfly valve is arranged on the seawater inlet pipe. The seawater pump extracts seawater from the seawater pool, and the seawater enters a space between the mesh tank shell and the outer stainless steel mesh clamp filter cloth pipe through the seawater electric butterfly valve. And a polymer purifying agent is filled in a mesh tank space between the outer stainless steel mesh clamp filter cloth pipe and the inner stainless steel mesh clamp filter cloth pipe. The polymeric scavenger comprises a solid polymer which may be selected from the group consisting of the base neutralized polymers polyethyleneimine hydrochloride, polyalkylene glycol, polyvinyl alcohol alkylene oxide polymer polyacryloyloxy glucose and copolymers thereof. And a polymer return pipe is arranged on a mesh tank sealing cover between the outer stainless steel mesh clamp filter cloth pipe and the inner stainless steel mesh clamp filter cloth pipe, and a polymer return electric butterfly valve is arranged on the polymer return pipe. An algae water pipe is arranged on the net tank sealing bottom between the net tank shell and the outer stainless steel net sandwich filter cloth pipe, and an algae water electric butterfly valve is arranged on the algae water pipe. And a polymer water pipe is arranged on the mesh tank sealing bottom between the outer stainless steel mesh clamp filter cloth pipe and the inner stainless steel mesh clamp filter cloth pipe, and a polymer water electric butterfly valve is arranged on the polymer water pipe. The net tank sealing bottom below the inner stainless steel net clip filtering cloth pipe is provided with a clean seawater pipe, and the outlet of the clean seawater pipe is arranged above the clean seawater pool. The structure of the algae centrifugal separator is similar to that of a centrifugal sugar sieving machine, and the structure of the algae centrifugal separator is as follows: the central shaft of the algae frame is fixed on the central line of the sediment frame, the central shaft of the algae frame upwards passes through the central bearing of the algae sealing cover and then is connected with the shaft of the algae motor through the coupler, and the algae motor and the algae sealing cover are fixed on the algae supporting frame. The algae sealing cover is provided with an algae water pipe outlet and an algae flushing water pipe outlet, and the algae flushing water pipe is provided with an algae flushing electromagnetic water valve. The clean seawater pump pumps clean seawater from the clean seawater pool, and a branch water pipe connected from the clean seawater pump is connected to the inlet of the algae washing electromagnetic water valve 23. The side surface of the algae frame is provided with an algae stainless steel net clamping filter cloth pipe, one side of the algae sealing bottom is fixed at one end of an algae lever, the other end of the algae lever is hinged with the lower end of the algae supporting frame, and the lower end of the algae longitudinal rod is hinged with the middle part of the algae lever. The algae control lever is sleeved with an algae tension spring, the upper end of the algae control lever is fixed on the algae electromagnet armature, and an algae pond is arranged below the algae sealed bottom. The alga shell covers the space between the alga sealed bottom and the alga sealed cover, a sealing ring is arranged between the alga shell and the alga sealed bottom as well as between the alga shell and the alga sealed cover, and air blown out by the alga air blower is blown out from a vertical gap on the alga shell. The algae shell is provided with an algae filtered water collecting tank, and an algae filtered water collecting pipe is arranged below the algae filtered water collecting tank. The structure of the polymer centrifugal separator is similar to that of a centrifugal sugar sieving machine, and the structure of the polymer centrifugal separator is as follows: the central shaft of the polymer frame is fixed on the central line of the polymer frame, the central shaft of the polymer frame upwards passes through the central bearing of the polymer sealing cover and then is connected with the polymer motor 33 through a coupler, and the polymer motor and the polymer sealing cover are fixed on the polymer supporting frame. The polymer sealing cover is provided with a polymer water pipe 17 outlet, a water vapor pipe outlet and a polymer flushing water pipe outlet. Steam generated by the boiler enters a steam gas storage tank through a steam one-way valve, and the steam in the steam gas storage tank enters a polymer stainless steel mesh clamp filter cloth pipe through a steam electromagnetic valve; the polymer flushing water pipe is provided with a polymer flushing electromagnetic water valve, and the clean seawater pump pumps clean seawater from the clean seawater pool. And the other branch water pipe connected from the clean sea water pump is connected to the inlet of the polymer flushing electromagnetic water valve. The side surface of the polymer frame is provided with a polymer stainless steel net clamp filter cloth pipe. One side of the polymer sealing bottom is fixed at one end of the polymer lever, the other end of the polymer lever is hinged with the lower end of the polymer supporting frame, and the lower end of the polymer operating rod is hinged with the middle of the polymer lever. The polymer control lever is sleeved with a polymer tension spring, the upper end of the polymer control lever is fixed on the polymer electromagnet armature, and a polymer pool is arranged below the polymer sealing bottom. The polymer shell covers the space between the polymer sealing bottom and the polymer sealing cover, and a sealing ring is respectively arranged between the polymer shell and the polymer sealing bottom as well as between the polymer shell and the polymer sealing cover. The air from the polymer blower is blown out of a vertical slit in the polymer housing. The polymer shell is provided with a polymer filtering water collecting tank, a polymer filtering water collecting pipe is arranged below the polymer filtering water collecting tank, the water outlet of the polymer filtering water collecting pipe is arranged above the algae pond, and the algae water pump pumps the water-containing algae in the algae pond to the mariculture fish pond. The water outlet of the algae filtering water collecting pipe is arranged above the polymer pool, and the polymer water pump pumps the regenerated polymer water in the polymer pool out to enter a space between the outer stainless steel net clamp filtering cloth pipe and the inner stainless steel net clamp filtering cloth pipe of the rotary net tank through the polymer return water electric butterfly valve.

A control method of seawater pretreatment equipment used in seawater desalination comprises the following steps: dirty sea water is pumped to stainless steel gyration net front end from the sea by dirty sea water pump, and gear reduction motor drives stainless steel gyration net and rotates, and silt is stayed in stainless steel gyration net, and the sea water passes stainless steel gyration net and flows to gyration shell bottom, then flows to the sea water pond from the sea water pipe, and silt flows to in the silt pond of gyration shell rear end below from stainless steel gyration net rear end. The seawater pump extracts seawater from the seawater pool, the seawater enters a space between the mesh tank shell and the outer stainless steel mesh clamp filtering cloth pipe through the seawater electric butterfly valve, and algae are filtered out when the seawater passes through the outer stainless steel mesh clamp filtering cloth pipe. The seawater containing small molecular organic matters enters the space of the mesh tank between the outer stainless steel mesh-sandwiched filter cloth pipe and the inner stainless steel mesh-sandwiched filter cloth pipe, and is subjected to affinity with the polymer purifying agent. The seawater without small molecular organic matters passes through the inner stainless steel mesh-clamped filter cloth pipe to reach the inner stainless steel mesh-clamped filter cloth pipe, and then flows from the clean seawater pipe to the clean seawater pool. After the set time is reached, a large amount of algae are gathered at the outer side of the outer stainless steel mesh clamp filter cloth pipe, and a large amount of polymer purifying agent is gathered at the outer side of the inner stainless steel mesh clamp filter cloth pipe. The computer controller opens the polymer backwater electric butterfly valve, the polymer water electric butterfly valve and the algae water electric butterfly valve, starts the polymer water pump and the driving motor, and the mesh tank motor rotates to drive the mesh tank central shaft, the inner stainless steel mesh clamp filter cloth pipe and the outer stainless steel mesh clamp filter cloth pipe to rotate. The inner side of the outer stainless steel mesh clamp filter cloth pipe is provided with a plurality of turbine blades which push seawater between the outer stainless steel mesh clamp filter cloth pipe and the inner stainless steel mesh clamp filter cloth pipe to pass through the outer stainless steel mesh clamp filter cloth pipe to drive away algae gathered outside the outer stainless steel mesh clamp filter cloth pipe, and the inner side of the inner stainless steel mesh clamp filter cloth pipe is provided with a plurality of turbine blades which push seawater in the inner stainless steel mesh clamp filter cloth pipe to pass through the inner stainless steel mesh clamp filter cloth pipe to drive away polymer purifying agents gathered outside the inner stainless steel mesh clamp filter cloth pipe. Seawater with high algae content between the mesh cage shell and the outer stainless steel mesh clamp filtering cloth pipe flows into the algae centrifugal separator through the opened algae water electric butterfly valve, the polymer water pump pumps regenerated polymer water in the polymer pool out and enters a space between the outer stainless steel mesh clamp filtering cloth pipe and the inner stainless steel mesh clamp filtering cloth pipe of the rotary mesh cage through the polymer water return electric butterfly valve, and the seawater with high polymer micromolecule-like organic matter content between the outer stainless steel mesh clamp filtering cloth pipe and the inner stainless steel mesh clamp filtering cloth pipe flows into the polymer centrifugal separator through the opened polymer water electric butterfly valve. And after the set time is reached, the computer controller closes the polymer backwater electric butterfly valve, the polymer water electric butterfly valve and the algae water electric butterfly valve, stops supplying power to the polymer water pump and the net tank motor, rotates the net tank to produce the purified seawater again, and the purified seawater flows into the purified seawater pool. The computer control instrument starts the algae motor, the algae motor drives the algae stainless steel net clamp filter cloth pipe to rotate from slow to fast, seawater in the algae stainless steel net clamp filter cloth pipe is thrown out to the algae filtered water collecting tank of the algae shell, and then the seawater flows into the polymer pool from the algae filtered water collecting tank. The algae motor drives the algae stainless steel net clamp filter cloth pipe to rotate from fast to slow after the algae motor rotates for a set time. The computer control instrument supplies power to the algae electromagnet, the algae flushing electromagnetic water valve, the algae blower and the sea water purifying pump, and the algae electromagnet pushes the algae control rod downwards to drive the algae lever to rotate downwards so that the algae sealing bottom rotates downwards. The wind from the algae blower enters the algae housing 27 to blow off the algae attached to the inner surface of the algae stainless steel sandwich filter cloth pipe. The clean seawater pump extracts clean seawater from the clean seawater pool, the clean seawater is sprayed into the algae stainless steel mesh clamp filter cloth pipe through the algae washing electromagnetic water valve, and algae in the algae stainless steel mesh clamp filter cloth pipe is washed into the algae pool by water sprayed by the algae washing water pipe. After the set time is reached, the computer control instrument stops supplying power to the algae motor, the algae electromagnet, the algae flushing electromagnetic water valve and the algae blower, the algae pull spring pulls the algae control rod upwards to drive the algae lever to rotate upwards so as to close the algae sealing bottom upwards; the water vapor generated by the boiler enters the water vapor storage tank through the water vapor one-way valve, and the computer control instrument starts the polymer motor. The polymer motor drives the polymer stainless steel mesh clamp filter cloth pipe to rotate from slow to fast, the polymer in the polymer stainless steel mesh clamp filter cloth pipe is separated from most of micromolecular organic matters, seawater containing a large amount of micromolecular organic matters is thrown out of the polymer stainless steel mesh clamp filter cloth pipe, is thrown into a polymer filtered water collecting tank of the polymer shell, and then flows into the algae pond from the polymer filtered water collecting tank. After the polymer motor rotates for a set time, the computer controller supplies power to the steam electromagnetic valve, steam in the steam storage tank enters the polymer stainless steel mesh-sandwiched filter cloth pipe through the opened steam electromagnetic valve, and residual polymer in the polymer stainless steel mesh-sandwiched filter cloth pipe is separated from micromolecular organic matters. The seawater containing a large amount of small molecular organic matters is thrown out from the polymer stainless steel net clamped filter cloth pipe, thrown into a polymer filtered water collecting tank of the polymer shell, and then flows into the algae pond from the polymer filtered water collecting tank. And after the steam electromagnetic valve is electrified for a set time, the computer controller stops supplying power to the steam electromagnetic valve. The polymer motor drives the polymer stainless steel net clamping filter cloth pipe to rotate from fast to slow, then the computer controller supplies power to the polymer electromagnet, the polymer flushing electromagnetic water valve and the polymer blower, the polymer electromagnet pushes the polymer control lever downwards, and the polymer lever is driven to rotate downwards to enable the polymer sealing bottom to rotate downwards. The air blown by the polymer blower enters the polymer shell to blow off the polymer attached to the inner surface of the polymer stainless steel sandwich filter cloth pipe. The clean seawater pump pumps clean seawater from the clean seawater pool, and the clean seawater is sprayed into the polymer stainless steel mesh filter cloth pipe through the polymer flushing electromagnetic water valve. The polymer in the filter cloth pipe of the polymer stainless steel net clamp is washed into the polymer pool by the water sprayed by the polymer washing water pipe. And after the set time is reached, the computer controller stops supplying power to the polymer motor, the polymer electromagnet, the polymer flushing electromagnetic water valve and the polymer blower. The polymer pull spring pulls the polymer operating lever upwards to drive the polymer lever to rotate upwards so that the polymer sealing bottom is closed upwards. And the computer control instrument stops supplying power to the clean seawater pump. The computer control instrument starts the algae water pump, and the algae water pump pumps the water-containing algae in the algae pond to the mariculture fishpond.

A seawater pretreatment device used in seawater desalination. The seawater pretreatment equipment consists of a stainless steel rotary net silt screening machine, a rotary ceramic tank, an algae centrifugal separator, a foamed ceramic evaporator and a delivery pump, and is controlled by a computer controller. The stainless steel rotary screen silt screening machine is made of a rotary shell, a stainless steel rotary screen, a gear reduction motor and a rotary support frame. The front part of the rotary shell 1 is obliquely arranged on the front rotary support frame and the rear rotary support frame, a front annular rail is arranged at the position close to the front end of the stainless steel rotary net 2, three front rollers arranged at the front section in the rotary shell are pressed on the front annular rail, a rear annular rail is arranged at the position close to the rear end of the stainless steel rotary net, and three rear rollers arranged at the rear section in the rotary shell 1 are pressed on the rear annular rail. The gear reduction motor is arranged on the front rotary support frame, a ring gear is arranged at a position close to the front ring track of the stainless steel rotary net, and an output gear of the gear reduction motor is meshed with the ring gear arranged on the stainless steel rotary net. An annular baffle is arranged in the rotary shell close to the rear end of the stainless steel rotary net, a seawater pipe is arranged at the bottom of the rotary shell 1 in front of the annular baffle, an outlet of the seawater pipe is arranged above the seawater pool, and a silt pool is arranged below the rear end of the rotary shell. The dirty seawater is pumped from the sea to the front end of the stainless steel rotary net by a dirty seawater pump. The rotary ceramic pot is composed of a ceramic pot shell, a ceramic pot sealing cover, a ceramic pot sealing bottom, an outer foam ceramic pipe, an inner foam ceramic pipe, a ceramic pot frame, a ceramic pot central shaft, a ceramic pot supporting frame and a ceramic pot motor. The inner surface of the ceramic pot shell is provided with a plurality of inclined scraping blades. The ceramic jar frame is equipped with outer foam ceramic pipe, interior foam ceramic pipe and ceramic jar center pin from outside to inside in proper order, and ceramic jar center pin upper end passes the sealed lid center bearing of ceramic jar, then is connected with the pivot of ceramic jar motor through the shaft coupling, and ceramic jar center pin lower extreme passes the sealed end center bearing of ceramic jar. The ceramic pot shell, the ceramic pot sealing cover, the ceramic pot sealing bottom and the ceramic pot motor 11' are fixed on the ceramic pot frame support frame. The ceramic pot sealing cover between the ceramic pot shell and the outer foam ceramic pipe is provided with a seawater inlet pipe, the seawater inlet pipe is provided with a seawater electric butterfly valve, and a seawater pump extracts seawater from a seawater pool and enters a space between the ceramic pot shell and the outer foam ceramic pipe through the seawater electric butterfly valve. And a polymer purifying agent is filled in the space of the ceramic tank between the outer foam ceramic tube and the inner foam ceramic tube. The polymeric scavenger comprises a solid polymer which may be selected from the group consisting of the base neutralized polymers polyethyleneimine hydrochloride, polyalkylene glycol, polyvinyl alcohol alkylene oxide polymer polyacryloyloxy glucose and copolymers thereof. And a polymer return pipe is arranged on a ceramic tank sealing cover between the outer foam ceramic pipe and the inner foam ceramic pipe. An algae water pipe is arranged on the sealing bottom of the ceramic tank between the ceramic tank shell 13' and the outer foam ceramic pipe, and an algae water electric butterfly valve is arranged on the algae water pipe. And a polymer outlet pipe is arranged on the sealing bottom of the ceramic tank between the outer foam ceramic pipe and the inner foam ceramic pipe, and a polymer outlet electric butterfly valve is arranged on the polymer outlet pipe. The sealed bottom of the ceramic pot below the inner foam ceramic pipe is provided with a clean seawater pipe, and the outlet of the clean seawater pipe is arranged above the clean seawater pool. The structure of the algae centrifugal separator is similar to that of a centrifugal sugar sieving machine, and the structure of the algae centrifugal separator is as follows: the central shaft of the algae frame is fixed on the central line of the sediment frame, the central shaft of the algae frame upwards passes through the central bearing of the algae sealing cover and then is connected with the shaft of the algae motor through the coupler, and the algae motor and the algae sealing cover are fixed on the algae supporting frame. The algae sealing cover is provided with an algae water pipe outlet and an algae flushing water pipe outlet, and the algae flushing water pipe is provided with an algae flushing electromagnetic water valve. The clean seawater pump pumps clean seawater from the clean seawater pool, and a branch water pipe connected from the clean seawater pump is connected to an inlet of the algae washing electromagnetic water valve. The side surface of the algae frame is provided with an algae stainless steel net clamping filter cloth pipe, one side of the algae sealed bottom is fixed at one end of an algae lever, the other end of the algae lever is hinged with the lower end of an algae supporting frame, the lower end of an algae longitudinal rod is hinged with the middle part of the algae lever, an algae tension spring is sleeved on the algae control rod, the upper end of the algae control rod is fixed on an algae electromagnet armature, and an algae pond is arranged below the algae sealed bottom. The alga shell covers the space between the alga sealed bottom and the alga sealed cover, and a sealing ring is respectively arranged between the alga shell and the alga sealed bottom as well as between the alga shell and the alga sealed cover. The wind blown by the algae blower is blown out from a vertical gap on the algae shell. The algae shell is provided with an algae filtered water collecting tank, an algae filtered water collecting pipe is arranged below the algae filtered water collecting tank, and the water outlet of the algae filtered water collecting pipe 41 is arranged above the algae filtered water tank. The pipeline connected with the algae filtering water pump is converged with the seawater pipe through the algae filtering backwater electromagnetic valve. The pipeline that comes out from the polymer exit tube goes out electric butterfly valve through the polymer, then passes through the left end swing joint of sealing washer and foamed ceramic evaporation pipe of foamed ceramic evaporimeter, and the right-hand member of foamed ceramic evaporation pipe of foamed ceramic evaporimeter passes through sealing washer swing joint to tee bend left interface, is equipped with the temperature sensor probe in the tee bend left interface. The evaporator motor drives the foamed ceramic evaporating pipe of the foamed ceramic evaporator to rotate through the gear, and the fuel oil burner is arranged below the rear section of the foamed ceramic evaporating pipe of the foamed ceramic evaporator. An oil pipe connected from the bottom of the fuel tank is connected to an inlet of the fuel pump, and the oil pipe connected from the outlet of the fuel pump is connected to an inlet of a nozzle of the fuel burner through an electric fuel regulating valve. An air pipe connected from the fuel oil blower is connected with the fuel oil burner through an electric adjusting air valve. An air outlet pipeline of the air compressor is connected to the top of the air storage tank through a one-way air valve, and a compressed air pressure sensor is mounted at the top of the air storage tank. An air pipe connected from the bottom of the air storage tank is connected to the top of the polymer tank through a compressed air electromagnetic valve, the top of the polymer tank is provided with a polymer pressure sensor, and a polymer purifying agent is filled in the polymer tank. The pipe from the bottom of the polymer tank 42' is connected to the upper port of the tee, the pipe from the lower port of the tee is connected to the inlet of the screw extrusion pump, and the outlet of the screw extrusion pump is connected to the inlet of the polymer return pipe.

A control method of seawater pretreatment equipment used in seawater desalination comprises the following steps: dirty sea water is pumped to stainless steel gyration net front end from the sea by dirty sea water pump, and gear reduction motor drives stainless steel gyration net and rotates, and silt stays in stainless steel gyration net, and the sea water passes stainless steel gyration net and flows to gyration shell bottom, then flows to the sea water pond from the sea water pipe, and silt flows to in the silt pond of gyration shell 1 rear end below from stainless steel gyration net rear end. The seawater pump extracts seawater from the seawater pool, the seawater enters a space between the ceramic tank shell and the outer foam ceramic pipe through the seawater electric butterfly valve, and algae are filtered out when the seawater passes through the outer foam ceramic pipe. The seawater containing small molecular organic matters enters the space of the ceramic tank between the outer foam ceramic tube and the inner foam ceramic tube and is subjected to affinity with the polymer purifying agent. The seawater without small molecular organic matters passes through the inner foamed ceramic pipe to reach the inner foamed ceramic pipe, and then flows from the clean seawater pipe to the clean seawater pool. A large amount of algae is accumulated outside the outer foamed ceramic tube. The computer controller opens the electric butterfly valve for the polymer to flow out and the electric butterfly valve for the algae water to start the ceramic irrigation motor, and the ceramic pot motor rotates to drive the ceramic pot central shaft, the inner foamed ceramic pipe and the outer foamed ceramic pipe to rotate. The algae outside the outer foam ceramic pipe is scraped by the scraping blade on the inner surface of the ceramic pot shell, transferred into the algae water pipe and then enters the algae centrifugal separator through the opened algae water electric butterfly valve. The computer control instrument starts the algae motor, the algae motor drives the algae stainless steel net clamp filter cloth pipe to rotate from slow to fast, seawater in the algae stainless steel net clamp filter cloth pipe is thrown out to the algae filtered water collecting tank of the algae shell, and then the seawater flows into the algae filtered water tank from the algae filtered water collecting pipe. The algae motor drives the algae stainless steel net clamp filter cloth pipe to rotate from fast to slow after the algae motor rotates for a set time. The computer control instrument supplies power to the algae electromagnet, the algae flushing electromagnetic water valve, the algae blower and the sea water purifying pump, and the algae electromagnet pushes the algae control rod downwards to drive the algae lever to rotate downwards so that the algae sealing bottom rotates downwards. The wind blown out by the algae blower enters the algae shell to blow off the algae attached to the inner surface of the algae stainless steel mesh clamp filter cloth pipe. The clean seawater pump extracts clean seawater from the clean seawater pool, the clean seawater is sprayed into the algae stainless steel mesh clamp filter cloth pipe through the algae washing electromagnetic water valve, and algae in the algae stainless steel mesh clamp filter cloth pipe is washed into the algae pool by water sprayed by the algae washing water pipe. And after the set time is reached, the computer control instrument stops supplying power to the algae motor, the algae electromagnet, the algae flushing electromagnetic water valve and the algae blower, and the algae tension spring pulls the algae control rod upwards to drive the algae lever to rotate upwards so as to close the algae sealing bottom upwards. The algae filtering water pump pumps the algae filtering water from the algae filtering water tank 44', the algae filtering water enters the seawater pipe through the opened algae filtering water returning electromagnetic valve, and the algae filtering water and the seawater in the seawater pipe are gathered together and then enter a space between the ceramic tank shell and the outer foam ceramic pipe. The computer control instrument starts the air compressor, and compressed air from the air compressor enters the air storage tank through the one-way air valve. When the compressed air pressure sensor detects that the pressure of the air storage tank reaches the set high air pressure, the computer control instrument stops supplying power to the air compressor, and the one-way air valve can prevent compressed air in the air storage tank from leaking out of the air compressor. When the compressed air pressure sensor detects that the pressure of the air storage tank is lower than the set low air pressure, the computer control instrument restarts the air compressor. Compressed air from the bottom of the air reservoir passes through the open compressed air solenoid valve and into the top of the polymer tank. When the polymer pressure sensor detects that the pressure of the polymer tank reaches the set high pressure, the computer control instrument closes the compressed air electromagnetic valve. When the polymer pressure sensor detects that the pressure of the polymer tank is lower than the set low pressure, the computer control instrument reopens the compressed air solenoid valve. The polymer depurative circulating system is pressurized by the polymer depurative with certain pressure in the polymer tank so as to reduce excessive seawater from remaining in the polymer depurative. Starting a screw extrusion pump, extracting a planning document agent from a polymer tank and a foamed ceramic evaporation pipe of a foamed ceramic evaporator by the screw extrusion pump, then sending the planning document agent into a gap between an outer foamed ceramic pipe and an inner foamed ceramic pipe through a polymer return pipe, extruding a polymer purifying agent which is compatible with micromolecule organic matters in the gap between the outer foamed ceramic pipe and the inner foamed ceramic pipe from a polymer outlet pipe arranged on a sealing bottom of the ceramic tank, and enabling the polymer purifying agent to enter the foamed ceramic evaporation pipe of the foamed ceramic evaporator through an opened polymer outlet electric butterfly valve to form circulation. In the front section of the foamed ceramic evaporation tube of the foamed ceramic evaporator, seawater in the polymer purifying agent is extruded to flow out from the pores of the foamed ceramic evaporation tube of the foamed ceramic evaporator. The computer control instrument starts the fuel pump, fuel oil from the bottom of the fuel tank enters the fuel pump, the fuel oil from the fuel pump enters the fuel oil burner through the electric fuel oil regulating valve, and the fuel oil is sprayed out from a nozzle of the fuel oil burner and then is ignited. And air blown out from the fuel oil blower enters the fuel oil burner through the electric adjusting air valve to support the combustion of fuel oil of the fuel oil burner. The computer controller starts the evaporator motor, and the evaporator motor drives the foamed ceramic evaporation tube of the foamed ceramic evaporator to rotate through the gear. The flame of the oil burner below the rear section of the ceramic foam evaporator tube 34' of the ceramic foam evaporator uniformly heats the polymer decontaminant containing a large amount of small molecular organic matter in the rear section of the ceramic foam evaporator tube. After the set temperature is reached, the micromolecular organic matters in the rear section of the foamed ceramic evaporation tube of the foamed ceramic evaporator are evaporated into gas which escapes from the micropores of the foamed ceramic evaporation tube section of the foamed ceramic evaporator. The temperature sensor probe arranged in the left connector of the tee joint detects that the temperature of the polymer purifying agent coming out of the foamed ceramic evaporation tube of the foamed ceramic evaporator reaches a set high temperature, and the computer control instrument reduces the fuel electric regulating valve and the electric regulating air valve so as to reduce the thermal power output by the fuel burner and reduce the temperature of the polymer purifying agent in the foamed ceramic evaporation tube of the foamed ceramic evaporator. The temperature sensor probe arranged in the left interface of the tee joint detects that the temperature of the polymer purifying agent coming out of the foamed ceramic evaporation tube of the foamed ceramic evaporator is lower than a set low temperature, and the computer control instrument enlarges the fuel electric regulating valve and the electric regulating air valve so as to increase the thermal power output by the fuel burner and improve the temperature of the polymer purifying agent in the foamed ceramic evaporation tube of the foamed ceramic evaporator.

Description of the drawings:

the present invention will be described in further detail with reference to the drawings and the detailed description.

FIG. 1 is a schematic structural view of a seawater pretreatment apparatus for desalinating seawater according to the present invention, which comprises a stainless steel rotary screen silt screening machine, a rotary screen tank, an algae centrifugal separator, a polymer centrifugal separator, and a transfer pump.

FIG. 2 is a schematic structural diagram of a seawater pretreatment apparatus for seawater desalination, which is composed of a stainless steel rotary screen silt screening machine, a rotary ceramic tank, an algae centrifugal separator, a foamed ceramic evaporator and a transfer pump.

The specific implementation mode is as follows:

fig. 1 shows a seawater pretreatment apparatus used in seawater desalination. The seawater pretreatment equipment consists of a stainless steel rotary net silt screening machine, a rotary net tank, an algae centrifugal separator, a polymer centrifugal separator and a delivery pump, and is controlled by a computer controller. The stainless steel rotary screen silt screening machine is made of a rotary shell 1, a stainless steel rotary screen 2, a gear reduction motor 3 and a rotary support frame. The front part of the rotary shell 1 is higher than the rear part thereof and is obliquely arranged on a front rotary support frame 4 and a rear rotary support frame 5, a front annular rail is arranged at a position close to the front end of the stainless steel rotary net 2, and three front rollers arranged at the front section in the rotary shell 1 are pressed on the front annular rail. A rear annular rail is arranged at a position close to the rear end of the stainless steel rotary net 2, and three rear rollers arranged at the rear section in the rotary shell 1 are pressed on the rear annular rail. The gear reduction motor 3 is arranged on the front rotary support frame 4, a ring gear is arranged at the position close to the front ring track of the stainless steel rotary net 2, and an output gear of the gear reduction motor 3 is meshed with the ring gear arranged on the stainless steel rotary net 2. An annular baffle is arranged in the rotary shell 1 close to the rear end of the stainless steel rotary net 2, a seawater pipe 6 is arranged at the bottom of the rotary shell 1 in front of the annular baffle, and an outlet of the seawater pipe 6 is arranged above the seawater pool 8. A silt pool 7 is arranged below the rear end of the rotary shell 1, and dirty seawater is pumped from the sea to the front end of the stainless steel rotary net 2 by a dirty seawater pump. The rotary mesh tank consists of a mesh tank shell 13, a mesh tank sealing cover, a mesh tank sealing bottom, an outer stainless steel mesh clamp filtering cloth pipe 14, an inner stainless steel mesh clamp filtering cloth pipe 15, a mesh tank frame, a mesh tank central shaft, a mesh tank supporting frame 12 and a mesh tank motor 11. A mesh tank frame is arranged in the mesh tank shell 13, an outer stainless steel mesh clamp filter cloth pipe 14, an inner stainless steel mesh clamp filter cloth pipe 15 and a mesh tank central shaft are sequentially arranged on the mesh tank frame from outside to inside, the upper end of the mesh tank central shaft penetrates through a mesh tank sealing cover central bearing and then is connected with a rotating shaft of a mesh tank motor 11 through a coupler, and the lower end of the mesh tank central shaft penetrates through a mesh tank sealing bottom central bearing. The net tank outer shell 13, the net tank sealing cover, the net tank sealing bottom and the net tank motor 11 are fixed on the net tank frame support frame 12. The inner side of the outer stainless steel mesh clamp filter cloth tube 14 is provided with a plurality of turbine blades, and the inner side of the inner stainless steel mesh clamp filter cloth tube 15 is provided with a plurality of turbine blades. A seawater inlet pipe is arranged on a mesh tank sealing cover between the mesh tank shell 13 and the outer stainless steel mesh clamp filtering cloth pipe 14, and a seawater electric butterfly valve 10 is arranged on the seawater inlet pipe. The seawater pump 9 pumps seawater from the seawater pool 8, and the seawater enters a space between the mesh tank shell 13 and the outer stainless steel sandwich filter cloth pipe 14 through the seawater electric butterfly valve 10. A polymer purifying agent is filled in the space of the mesh tank between the outer stainless steel mesh clamp filter cloth pipe 14 and the inner stainless steel mesh clamp filter cloth pipe 15. The polymeric scavenger comprises a solid polymer which may be selected from the group consisting of the base neutralized polymers polyethyleneimine hydrochloride, polyalkylene glycol, polyvinyl alcohol alkylene oxide polymer polyacryloyloxy glucose and copolymers thereof. And a polymer water return pipe is arranged on a mesh tank sealing cover between the outer stainless steel mesh-clamped filter cloth pipe 14 and the inner stainless steel mesh-clamped filter cloth pipe 15, and a polymer water return electric butterfly valve 46 is arranged on the polymer water return pipe. An algae water pipe 16 is arranged on the sealing bottom of the mesh tank between the mesh tank shell 13 and the outer stainless steel mesh sandwich filter cloth pipe 14, and an algae water electric butterfly valve 19 is arranged on the algae water pipe. A polymer water pipe 17 is arranged on the sealed bottom of the mesh tank between the outer stainless steel mesh-sandwiched filter cloth pipe 14 and the inner stainless steel mesh-sandwiched filter cloth pipe 15, and a polymer water electric butterfly valve 20 is arranged on the polymer water pipe 17. The net tank sealing bottom below the inner stainless steel net clip filtering cloth pipe 15 is provided with a clean seawater pipe 18, and the outlet of the clean seawater pipe 18 is arranged above the clean seawater pool 21. The structure of the algae centrifugal separator is similar to that of a centrifugal sugar sieving machine, and the structure of the algae centrifugal separator is as follows: the central shaft of the algae frame is fixed on the central line of the sediment frame, the central shaft of the algae frame upwards passes through the central bearing of the algae sealing cover and then is connected with the algae motor 25 through the shaft coupling, and the algae motor 25 and the algae sealing cover are fixed on the algae supporting frame 30. The algae sealing cover is provided with an algae water pipe 16 outlet and an algae flushing water pipe outlet, and the algae flushing water pipe is provided with an algae flushing electromagnetic water valve 23. The clean sea water pump 22 pumps clean sea water from the clean sea water pool 21, and a branch water pipe connected from the clean sea water pump 22 is connected to an inlet of the algae washing electromagnetic water valve 23. The side of the algae frame is provided with an algae stainless steel net clamping filter cloth pipe 26, one side of an algae sealing bottom 29 is fixed at one end of an algae lever, the other end of the algae lever is hinged with the lower end of an algae supporting frame 30, and the lower end of an algae longitudinal rod is hinged with the middle part of the algae lever. The algae control rod is sleeved with an algae tension spring 32, the upper end of the algae control rod is fixed on an armature iron of an algae electromagnet 31, and an algae pond 43 is arranged below the algae sealing bottom 29. The algae shell 27 covers the space between the algae sealed bottom and the algae sealed cover, a sealing ring is respectively arranged between the algae shell 27 and the algae sealed bottom 29 and the algae sealed cover, and air blown by the algae blower 28 is blown out from a vertical gap on the algae shell 27. The algae casing 27 is provided with an algae filtered water collecting tank, and an algae filtered water collecting pipe 41 is arranged below the algae filtered water collecting tank. The structure of the polymer centrifugal separator is similar to that of a centrifugal sugar sieving machine, and the structure of the polymer centrifugal separator is as follows: the central shaft of the polymer frame is fixed on the central line of the polymer frame, the central shaft of the polymer frame upwards passes through the central bearing of the polymer sealing cover and then is connected with the polymer motor 33 through a coupler, and the polymer motor 33 and the polymer sealing cover are fixed on the polymer supporting frame 38. The polymer sealing cover is provided with a polymer water pipe 17 outlet, a water vapor pipe outlet and a polymer flushing water pipe outlet. The water vapor generated by the boiler 47 enters a water vapor storage tank 49 through a water vapor one-way valve 48, and the water vapor in the water vapor storage tank 49 enters the polymer stainless steel sandwich filter cloth tube 34 through a water vapor electromagnetic valve 50; the polymer flushing water pipe is provided with a polymer flushing electromagnetic water valve 24, and the clean sea water pump 22 pumps clean sea water from the clean sea water basin 21. The other branch water pipe connected from the clean sea water pump 22 is connected to the inlet of the polymer flushing electromagnetic water valve 24. The polymer frame is provided with a polymer stainless steel net clip filter cloth tube 34 on the side. One side of the polymer sealing bottom 37 is fixed at one end of the polymer lever, the other end of the polymer lever is hinged with the lower end of the polymer supporting frame 38, and the lower end of the polymer operating rod is hinged with the middle of the polymer lever. The polymer control rod is sleeved with a polymer tension spring 40, the upper end of the polymer control rod is fixed on a polymer electromagnet armature 39, and a polymer pool 44 is arranged below the polymer sealing bottom 37. The polymer housing 35 houses the polymer seal base 37 and the polymer seal cap, with a seal ring between the polymer housing and each of the polymer seal base and the polymer seal cap. The air from the polymer blower 36 is blown out from a vertical slit on the polymer housing 35. The polymer shell 35 is provided with a polymer filtered water collecting tank, a polymer filtered water collecting pipe 42 is arranged below the polymer filtered water collecting tank, the water outlet of the polymer filtered water collecting pipe 42 is arranged above an algae pond 43, and the algae water pump pumps the water-containing algae in the algae pond to the mariculture fishpond. The outlet of the algae filtered water collecting pipe 41 is arranged above the polymer pool, and the polymer water pump 45 pumps the regenerated polymer water in the polymer pool 42 out to enter the space between the outer stainless steel mesh-sandwiched filter cloth pipe 14 and the inner stainless steel mesh-sandwiched filter cloth pipe 15 of the rotary mesh tank through the polymer return electric butterfly valve 46.

Fig. 1 shows a control method of a seawater pretreatment apparatus used in seawater desalination: dirty sea water is pumped to stainless steel rotary net 2 front end from the sea by dirty sea water pump, gear motor 3 drives stainless steel rotary net 2 and rotates, and silt remains in stainless steel rotary net 2, and the sea water passes stainless steel rotary net 2 and flows to gyration shell 1 bottom, then flows to sea water pond 8 from sea water pipe 6, and silt flows to in the silt pond 8 of gyration shell 1 rear end below from stainless steel rotary net 2 rear end. The seawater pump 9 extracts seawater from the seawater pool 8, the seawater enters a space between the mesh tank shell 13 and the outer stainless steel mesh-sandwiched filter cloth pipe 14 through the seawater electric butterfly valve 10, and algae are filtered out when the seawater passes through the outer stainless steel mesh-sandwiched filter cloth pipe 14. The seawater containing small molecular organic matters enters the space between the outer stainless steel sandwich filter cloth pipe 14 and the inner stainless steel sandwich filter cloth pipe 15, and is subjected to affinity with the polymer purifying agent. The seawater lost small molecular organic matters passes through the inner stainless steel mesh-sandwiched filter cloth tube 15 into the inner stainless steel mesh-sandwiched filter cloth tube 15, and then flows from the clean seawater tube 18 to the clean seawater pool 21. After the set time is reached, a large amount of algae is gathered outside the outer stainless steel mesh-sandwiched filter cloth pipe 14, and a large amount of polymer purifying agent is gathered outside the inner stainless steel mesh-sandwiched filter cloth pipe 15. The computer controller opens the polymer backwater electric butterfly valve 46, the polymer water electric butterfly valve 20 and the algae water electric butterfly valve 19, and starts the polymer water pump 45 and the mesh tank motor 11, and the mesh tank motor 11 rotates to drive the mesh tank central shaft, the inner stainless steel mesh-sandwiched filter cloth pipe 15 and the outer stainless steel mesh-sandwiched filter cloth pipe 14 to rotate. The inner side of the outer stainless steel mesh clamp filter cloth pipe 14 is provided with a plurality of turbine blades which push seawater between the outer stainless steel mesh clamp filter cloth pipe 14 and the inner stainless steel mesh clamp filter cloth pipe 15 to pass through the outer stainless steel mesh clamp filter cloth pipe 14 to drive away algae gathered at the outer side of the outer stainless steel mesh clamp filter cloth pipe 14, and the inner side of the inner stainless steel mesh clamp filter cloth pipe 15 is provided with a plurality of turbine blades which push seawater in the inner stainless steel mesh clamp filter cloth pipe 15 to pass through the inner stainless steel mesh clamp filter cloth pipe 15 to drive away polymer purifying agents gathered at the outer side of the inner stainless steel mesh clamp filter cloth pipe 15. Seawater with high algae content between the mesh tank shell 13 and the outer stainless steel mesh-sandwiched filter cloth pipe 14 flows into the algae centrifugal separator through the opened algae water electric butterfly valve 19, the polymer water pump 45 pumps regenerated polymer water in the polymer pool 44 out and enters a space between the outer stainless steel mesh-sandwiched filter cloth pipe 14 and the inner stainless steel mesh-sandwiched filter cloth pipe 15 of the rotary mesh tank through the polymer water return electric butterfly valve 46, and seawater with high polymer micromolecule-philic organic matter content between the outer stainless steel mesh-sandwiched filter cloth pipe 14 and the inner stainless steel mesh-sandwiched filter cloth pipe 15 flows into the polymer centrifugal separator through the opened polymer water electric butterfly valve 20. After the set time is reached, the computer controller closes the polymer water return electric butterfly valve 46, the polymer water electric butterfly valve 20 and the algae water electric butterfly valve 19, and stops supplying power to the polymer water pump 45 and the net tank motor 11, the net tank is rotated to produce clean seawater again, and the clean seawater flows into the clean seawater pool 21. The computer control instrument starts the algae motor 25, the algae motor 25 drives the algae stainless steel net clamp filtering cloth pipe 26 to rotate from slow to fast, seawater in the algae stainless steel net clamp filtering cloth pipe 26 is thrown out to the algae filtered water collecting tank of the algae shell 27, and then the seawater flows to the polymer pool 44 from the algae filtered water collecting pipe 41. After the algae motor 25 rotates for a set time, the algae motor 25 drives the algae stainless steel net clamp filter cloth pipe 26 to rotate from fast to slow. The computer control instrument supplies power to the algae electromagnet 31, the algae washing electromagnetic water valve 23, the algae blower 28 and the sea water purifying pump 22, and the algae electromagnet 31 pushes the algae control rod downwards to drive the algae lever to rotate downwards so as to rotate the algae sealing bottom 29 downwards. The wind from the algae blower 28 enters the algae housing 27 to blow off the algae attached to the inner surface of the algae stainless steel sandwich filter cloth tube 26. The clean seawater pump 22 pumps clean seawater from the clean seawater pool 21, the clean seawater is sprayed into the algae stainless steel net clamping filter cloth pipe 26 through the algae washing electromagnetic water valve 23, and algae in the algae stainless steel net clamping filter cloth pipe 26 is washed into the algae pool 43 by water sprayed by the algae washing water pipe. After the set time is reached, the computer control instrument stops supplying power to the algae motor 25, the algae electromagnet 31, the algae flushing electromagnetic water valve 23 and the algae blower 28, the algae tension spring 32 spring pulls the algae control rod upwards, and the algae lever is driven to rotate upwards to close the algae sealing bottom 29 upwards; the water vapor generated by the boiler 47 enters a water vapor storage tank 49 through a water vapor one-way valve 48, and the computer control instrument starts the polymer motor 33. The polymer motor 33 drives the polymer stainless steel mesh-sandwiched filter cloth pipe 34 to rotate from slow to fast, the polymer in the polymer stainless steel mesh-sandwiched filter cloth pipe 34 is separated from most of the small molecular organic matters, seawater containing a large amount of the small molecular organic matters is thrown out of the polymer stainless steel mesh-sandwiched filter cloth pipe 34 and thrown into the polymer filtered water collecting tank of the polymer shell 35, and then flows into the algae pond 43 from the polymer filtered water collecting pipe 34. After the polymer motor 33 rotates for a set time, the computer controller supplies power to the steam electromagnetic valve 50, and the steam in the steam storage tank 49 enters the polymer stainless steel sandwich filter cloth pipe 34 through the opened steam electromagnetic valve 50 to separate the residual polymer in the polymer stainless steel sandwich filter cloth pipe 34 from the micromolecule organic matter. The seawater containing a large amount of small molecular organic matters is thrown from the polymer stainless steel mesh-sandwiched filter cloth pipe 34 into the polymer filtered water collecting tank of the polymer housing 35, and then flows from the polymer filtered water collecting pipe 42 into the algae pond 43. After the steam electromagnetic valve 50 is electrified for a set time, the computer controller stops supplying power to the steam electromagnetic valve 50. The polymer motor 33 drives the polymer stainless steel net clamp filter cloth pipe 34 to rotate from fast to slow, then the computer controller supplies power to the polymer electromagnet 39, the polymer flushing electromagnetic water valve 24 and the polymer blower 36, the polymer electromagnet 39 pushes the polymer control rod downwards, and the polymer lever is driven to rotate downwards to enable the polymer sealing bottom 37 to rotate downwards. The air from the polymer blower 33 enters the polymer housing 35 to blow off the polymer attached to the inner surface of the polymer stainless steel sandwich filter cloth tube 34. The clean seawater pump 22 pumps clean seawater from the clean seawater pool 21, and the clean seawater is sprayed into the polymer stainless steel mesh filter cloth pipe 34 through the polymer flushing electromagnetic water valve 24. The polymer in the polymer stainless steel mesh-sandwiched filter cloth tube 34 is flushed into the polymer tank 44 by water from the polymer flush tube. After the set time is reached, the computer controller stops supplying power to the polymer motor 33, the polymer electromagnet 39, the polymer flushing electromagnetic water valve 24 and the polymer blower 36. The polymer pull spring 40 pulls the polymer lever upward, causing the polymer lever to rotate upward closing the polymer seal bottom 37 upward. The computer control stops supplying power to the clean seawater pump 22. The computer control instrument starts the algae water pump, and the algae water pump pumps the water-containing algae in the algae pond to the mariculture fishpond.

In practical use, as shown in fig. 1, seawater containing a large amount of small molecular organic substances is thrown from the polymer stainless steel mesh filter cloth pipe 34 into the polymer filtered water collecting tank of the polymer housing 35, and then flows from the polymer filtered water collecting pipe 42 to the burst oxygen purification tank. The explosive oxygen purification pool is filled with drugs, the micromolecular organic matters are decomposed into inorganic matters under the action of the drugs and oxygen in the air, the micromolecular organic matters in seawater in the explosive oxygen purification pool are removed, and then the regenerated seawater is pumped into the polymer pool 44 for reuse.

As shown in FIG. 1, the polymer after being dried is distilled to remove small molecular organic matters and then is put into a polymer pool, and the algae filtered water collecting pipe 41 flows into the polymer pool 44 to be mixed with the polymer.

Fig. 2 shows a seawater pretreatment apparatus used in seawater desalination. The seawater pretreatment equipment consists of a stainless steel rotary net silt screening machine, a rotary ceramic tank, an algae centrifugal separator, a foamed ceramic evaporator and a delivery pump, and is controlled by a computer controller. The stainless steel rotary screen silt screening machine is made of a rotary shell 1, a stainless steel rotary screen 2, a gear reduction motor 3 and a rotary support frame. The front part of the rotary shell 1 is obliquely arranged on the front rotary support frame 4 and the rear rotary support frame 5, a front annular rail is arranged at the position close to the front end of the stainless steel rotary net 2, three front rollers arranged at the front section in the rotary shell 1 are pressed on the front annular rail, a rear annular rail is arranged at the position close to the rear end of the stainless steel rotary net 2, and three rear rollers arranged at the rear section in the rotary shell 1 are pressed on the rear annular rail. The gear reduction motor 3 is arranged on the front rotary support frame 4, a ring gear is arranged at the position close to the front ring track of the stainless steel rotary net 2, and an output gear of the gear reduction motor 3 is meshed with the ring gear arranged on the stainless steel rotary net 2. An annular baffle is arranged in the rotary shell 1 close to the rear end of the stainless steel rotary net 2, a seawater pipe 6 is arranged at the bottom of the rotary shell 1 in front of the annular baffle, an outlet of the seawater pipe 6 is arranged above a seawater pool 8, and a silt pool 7 is arranged below the rear end of the rotary shell 1. The dirty seawater is pumped from the sea to the front end of the stainless steel rotary net 2 by a dirty seawater pump. The rotary ceramic pot consists of a ceramic pot shell 13 ', a ceramic pot sealing cover, a ceramic pot sealing bottom, an outer foam ceramic tube 14 ', an inner foam ceramic tube 15 ', a ceramic pot frame, a ceramic pot central shaft, a ceramic pot support frame 12 ' and a ceramic pot motor 11 '. The inner surface of the ceramic pot housing 13' is provided with a plurality of inclined scraping blades. The ceramic pot frame is sequentially provided with an outer foam ceramic tube 14 ', an inner foam ceramic tube 15 ' and a ceramic pot center shaft from outside to inside, the upper end of the ceramic pot center shaft penetrates through a ceramic pot sealing cover center bearing and then is connected with a rotating shaft of a ceramic pot motor 11 ' through a coupler, and the lower end of the ceramic pot center shaft penetrates through a ceramic pot sealing bottom center bearing. The ceramic pot shell 13 ', the ceramic pot sealing cover, the ceramic pot sealing bottom and the ceramic pot motor 11 ' are fixed on the ceramic pot frame support frame 12 '. A seawater inlet pipe is arranged on a ceramic tank sealing cover between the ceramic tank shell 13 'and the outer foam ceramic pipe 14', a seawater electric butterfly valve 10 is arranged on the seawater inlet pipe, and a seawater pump 9 extracts seawater from the seawater pool 8 and enters a space between the ceramic tank shell 13 'and the outer foam ceramic pipe 14' through the seawater electric butterfly valve 10. The space of the ceramic tank between the outer foamed ceramic tube 14 'and the inner foamed ceramic tube 15' is filled with a polymer purifying agent. The polymeric scavenger comprises a solid polymer which may be selected from the group consisting of the base neutralized polymers polyethyleneimine hydrochloride, polyalkylene glycol, polyvinyl alcohol alkylene oxide polymer polyacryloyloxy glucose and copolymers thereof. A polymer return pipe is arranged on the ceramic tank sealing cover between the outer foamed ceramic pipe 14 'and the inner foamed ceramic pipe 15'. An algae water pipe 16 is arranged on the sealing bottom of the ceramic tank between the ceramic tank shell 13 'and the outer foam ceramic pipe 14', and an algae water electric butterfly valve 19 is arranged on the algae water pipe 16. The polymer outlet pipe 17 ' is arranged on the sealing bottom of the ceramic pot between the outer foamed ceramic pipe 14 ' and the inner foamed ceramic pipe 15 ', and the polymer outlet electric butterfly valve 20 ' is arranged on the polymer outlet pipe 17 '. The sealed bottom of the ceramic pot below the inner foam ceramic pipe 15' is provided with a clean seawater pipe 18, and the outlet of the clean seawater pipe 18 is arranged above a clean seawater pool 21. The structure of the algae centrifugal separator is similar to that of a centrifugal sugar sieving machine, and the structure of the algae centrifugal separator is as follows: the central shaft of the algae frame is fixed on the central line of the sediment frame, the central shaft of the algae frame upwards passes through the central bearing of the algae sealing cover and then is connected with the algae motor 25 through the shaft coupling, and the algae motor 25 and the algae sealing cover are fixed on the algae supporting frame 30. The algae sealing cover is provided with an algae water pipe 16 outlet and an algae flushing water pipe outlet, and the algae flushing water pipe is provided with an algae flushing electromagnetic water valve 23. The clean sea water pump 22 pumps clean sea water from the clean sea water pool 21, and a branch water pipe connected from the clean sea water pump 22 is connected to an inlet of the algae washing electromagnetic water valve 23. The side surface of the algae frame is provided with an algae stainless steel net clamping filter cloth pipe 26, one side of an algae sealing bottom 29 is fixed at one end of an algae lever, the other end of the algae lever is hinged with the lower end of an algae supporting frame 30, the lower end of an algae longitudinal rod is hinged with the middle part of the algae lever, an algae tension spring 32 is sleeved on the algae control rod, the upper end of the algae control rod is fixed on an armature iron of an algae electromagnet 31, and an algae pond 43 is arranged below the algae sealing bottom 29. The algae shell 27 covers the space between the algae sealed bottom and the algae sealed cover, and a sealing ring is respectively arranged between the algae shell 27 and the algae sealed bottom 29 as well as between the algae sealed cover and the algae sealed cover. The wind from the algae blower 28 is blown out from a vertical slit in the algae housing 27. The algae casing 27 is provided with an algae filtered water collecting tank, an algae filtered water collecting pipe 41 is arranged below the algae filtered water collecting tank, and the water outlet of the algae filtered water collecting pipe 41 is arranged above the algae filtered water pond 44'. The pipeline from the algae filtering water pump 45 'is collected with the seawater pipe through the algae filtering backwater electromagnetic valve 46'. The pipeline from the polymer outlet pipe 17 'passes through the polymer outlet electric butterfly valve 20' and then is movably connected with the left end of a foamed ceramic evaporation pipe 34 'of the foamed ceramic evaporator through a sealing ring, the right end of the foamed ceramic evaporation pipe 34' of the foamed ceramic evaporator is movably connected with the left connector of a tee joint through the sealing ring, and a temperature sensor probe is arranged in the left connector of the tee joint. An evaporator motor 35 'drives a foamed ceramic evaporation tube 34' of the foamed ceramic evaporator to rotate through a gear, and an oil burner 35 'is arranged below the rear section of the foamed ceramic evaporation tube 34' of the foamed ceramic evaporator. The oil pipe from the bottom of the fuel tank 47 ' is connected to the inlet of the fuel pump 48 ', and the oil pipe from the outlet of the fuel pump 48 ' is connected to the inlet of the nozzle of the fuel burner 35 ' through the electric fuel regulating valve 49 '. The air pipe connected from the fuel blower 50 ' is connected to the fuel burner 35 ' through the electric adjusting air valve 51 '. The air outlet pipe of the air compressor 37 'is connected to the top of an air storage tank 39' through a one-way air valve 38 ', and a compressed air pressure sensor is arranged at the top of the air storage tank 39'. The air pipe from the bottom of the air storage tank 39 ' is connected to the top of the polymer tank 42 ' through the compressed air solenoid valve 40 ', the polymer pressure sensor is arranged at the top of the polymer tank 42 ', and the polymer purifying agent is arranged in the polymer tank 42 '. The pipe from the bottom of the polymer tank 42 ' is connected to the upper port of the tee, the pipe from the lower port of the tee is connected to the inlet of the screw extrusion pump 36 ', and the outlet of the screw extrusion pump 36 ' is connected to the inlet of the polymer return pipe.

As shown in fig. 2, a control method of a seawater pretreatment apparatus used in seawater desalination is as follows: dirty sea water is pumped to stainless steel rotary net 2 front end from the sea by dirty sea water pump, gear motor 3 drives stainless steel rotary net 2 and rotates, and silt remains in stainless steel rotary net 2, and the sea water passes stainless steel rotary net 2 and flows to gyration shell 1 bottom, then flows to sea water pond 8 from sea water pipe 6, and silt flows to in the silt pond 8 of gyration shell 1 rear end below from stainless steel rotary net 2 rear end. The seawater pump 9 pumps seawater from the seawater pool 8, the seawater enters a space between the ceramic tank shell 13 ' and the outer foam ceramic pipe 14 ' through the seawater electric butterfly valve 10, and algae are filtered out when the seawater passes through the outer foam ceramic pipe 14 '. The seawater containing small molecular organic matters enters the space of the ceramic tank between the outer foamed ceramic tube 14 'and the inner foamed ceramic tube 15' and is subjected to affinity with the polymer purifying agent. The seawater from which the small molecule organic matters are lost passes through the inner foamed ceramic tube 15 'to the inside of the inner foamed ceramic tube 15' and then flows from the clean seawater tube 18 to the clean seawater pool 21. A large amount of algae is accumulated outside the outer foamed ceramic tube 14'. The computer controller opens the polymer outlet electric butterfly valve 20 ', the algae water electric butterfly valve 19, and starts the ceramic tank motor 11 ', and the ceramic tank motor 11 ' rotates to drive the ceramic tank central shaft, the inner foam ceramic tube 15 ' and the outer foam ceramic tube 14 ' to rotate. The algae outside the outer foam ceramic tube 14 'is scraped by the scraping blades on the inner surface of the ceramic pot shell 13' and transferred into the algae water tube 16, and then enters the algae centrifugal separator through the opened algae water electric butterfly valve 19. The computer control instrument starts the algae motor 25, the algae motor 25 drives the algae stainless steel net clamp filtering cloth pipe 26 to rotate from slow to fast, seawater in the algae stainless steel net clamp filtering cloth pipe 26 is thrown out to the algae filtering water collecting tank of the algae shell 27, and then the seawater flows to the algae filtering water tank 44' from the algae filtering water collecting pipe 41. After the algae motor 25 rotates for a set time, the algae motor 25 drives the algae stainless steel net clamp filter cloth pipe 26 to rotate from fast to slow. The computer control instrument supplies power to the algae electromagnet 31, the algae washing electromagnetic water valve 23, the algae blower 28 and the sea water purifying pump 22, and the algae electromagnet 31 pushes the algae control rod downwards to drive the algae lever to rotate downwards so as to rotate the algae sealing bottom 29 downwards. The wind from the algae blower 28 enters the algae housing 27 to blow off the algae attached to the inner surface of the algae stainless steel sandwich filter cloth tube 26. The clean seawater pump 22 pumps clean seawater from the clean seawater pool 21, the clean seawater is sprayed into the algae stainless steel net clamping filter cloth pipe 26 through the algae washing electromagnetic water valve 23, and algae in the algae stainless steel net clamping filter cloth pipe 26 is washed into the algae pool 43 by water sprayed by the algae washing water pipe. After the set time is reached, the computer controller stops supplying power to the algae motor 25, the algae electromagnet 31, the algae flushing electromagnetic water valve 23 and the algae blower 28, and the algae tension spring 32 spring pulls the algae control lever upwards to drive the algae lever to rotate upwards so as to close the algae sealing bottom 29 upwards. The algae filtering water pump 45 ' extracts algae filtering water from the algae filtering water pool 44 ', the algae filtering water enters the seawater pipe through the opened algae filtering water return electromagnetic valve 46 ', and the algae filtering water and the seawater in the seawater pipe are gathered together and then enter a space between the ceramic tank shell 13 ' and the outer foam ceramic pipe 14 '. The computer control activates the air compressor 37 'and compressed air from the air compressor 37' passes through the one-way air valve 38 'and into the air reservoir 39'. When the compressed air pressure sensor detects that the pressure of the air storage tank 39 ' reaches the set high pressure, the computer control instrument stops supplying power to the air compressor 37 ', and the one-way air valve 38 ' can prevent the compressed air in the air storage tank 39 ' from leaking out of the air compressor 37 '. When the compressed air pressure sensor detects that the pressure of the air storage tank 39 'is lower than the set low air pressure, the computer control instrument restarts the air compressor 37'. Compressed air from the bottom of the air reservoir 39 ' passes through the open compressed air solenoid valve 40 ' and into the top of the polymer tank 42 '. When the polymer pressure sensor detects that the pressure of the polymer tank 42 'reaches the set high pressure, the computer controller closes the compressed air solenoid valve 40'. When the polymer pressure sensor detects that the pressure in the polymer tank 42 'is below the set low pressure, the computer control re-opens the compressed air solenoid valve 40'. The polymer depurative circulating system is pressurized by the polymer depurative having a certain pressure in the polymer tank 42' to reduce excessive seawater from remaining in the polymer depurative. And starting a screw extrusion pump 36 ', wherein the screw extrusion pump 36 ' extracts a planning document agent from a polymer tank 42 ' and a foamed ceramic evaporation pipe 34 ' of the foamed ceramic evaporator, then the planning document agent is conveyed into a gap between an outer foamed ceramic pipe 14 ' and an inner foamed ceramic pipe 15 ' through a polymer return pipe, a polymer purifying agent which is in the gap between the outer foamed ceramic pipe 14 ' and the inner foamed ceramic pipe 15 ' and has affinity with small molecular organic matters is extruded from a polymer outlet pipe 17 ' arranged on the sealing bottom of the ceramic tank, and the polymer purifying agent enters the foamed ceramic evaporation pipe 34 ' of the foamed ceramic evaporator through an opened polymer outlet electric butterfly valve 20 ' to form circulation. In the front section of the foamed ceramic evaporator 34 ', seawater in the polymer purifying agent is extruded to flow out from the pores of the foamed ceramic evaporator 34' of the foamed ceramic evaporator. The computer control unit starts the fuel pump 48 ', the fuel from the bottom of the fuel tank 47 ' enters the fuel pump 48 ', the fuel from the fuel pump 48 ' enters the fuel burner 35 ' through the electric fuel regulating valve 49 ', and is jetted from the nozzle of the fuel burner 35 ' and then ignited. The air blown from the fuel blower 50 'enters the fuel burner 35' through the electric adjustment air valve 51 'to support the combustion of the fuel burner 35'. The computer controller starts the evaporator motor 35 ', and the evaporator motor 35 ' drives the foamed ceramic evaporation tube 34 ' of the foamed ceramic evaporator to rotate through the gear. The flame of the oil burner 35 ' below the rear section of the ceramic foam evaporator tube 34 ' of the ceramic foam evaporator uniformly heats the polymer depurative containing a large amount of small molecular organic matters in the rear section of the ceramic foam evaporator tube 34 ' of the ceramic foam evaporator. After the set temperature is reached, the small molecular organic matters in the rear section of the foamed ceramic evaporation tube 34 'of the foamed ceramic evaporator are evaporated into gas, and the gas escapes from the micropores in the rear section of the foamed ceramic evaporation tube 34' of the foamed ceramic evaporator. The temperature sensor probe arranged in the left interface of the tee joint detects that the temperature of the polymer purifying agent coming out of the foamed ceramic evaporation tube 34 ' of the foamed ceramic evaporator reaches a set high temperature, and the computer control instrument reduces the fuel electric regulating valve 49 ' and the electric regulating air valve 51 ' so as to reduce the thermal power output by the fuel burner 35 ' and reduce the temperature of the polymer purifying agent in the foamed ceramic evaporation tube 34 ' of the foamed ceramic evaporator. The temperature sensor probe arranged in the left interface of the tee joint detects that the temperature of the polymer purifying agent coming out of the foamed ceramic evaporation tube 34 ' of the foamed ceramic evaporator is lower than the set low temperature, and the computer control instrument increases the fuel electric regulating valve 49 ' and the electric regulating air valve 51 ' so as to increase the thermal power output by the fuel burner 35 ' and improve the temperature of the polymer purifying agent in the foamed ceramic evaporation tube 34 ' of the foamed ceramic evaporator.

The reverse osmosis seawater desalination system for clean seawater and the purification system for brackish water use very low direct current voltage to drive off salt in the brackish water, and then use very low water pressure to carry out reverse osmosis seawater desalination on the seawater without backwashing semipermeable membrane. Or the salt in the brackish water is driven away by using a very low direct current voltage, and then the forward osmosis seawater desalination is carried out on the seawater by using a lower water pressure.

Claims

1. A seawater pretreatment device used in seawater desalination is characterized in that: the seawater pretreatment equipment consists of a stainless steel rotary screen silt screening machine, a rotary screen tank, an algae centrifugal separator, a polymer centrifugal separator and a delivery pump, and is controlled by a computer controller; the stainless steel rotating net silt screening machine is made of a rotating shell (1), a stainless steel rotating net (2), a gear reduction motor (3) and a rotating support frame, wherein the rotating shell (1) is obliquely arranged on a front rotating support frame (4) and a rear rotating support frame (5) in a high-back low-back manner, a front annular rail is arranged at a position close to the front end of the stainless steel rotating net (2), three front rollers arranged at the front section in the rotating shell (1) are pressed on the front annular rail, a rear annular rail is arranged at a position close to the rear end of the stainless steel rotating net (2), three rear rollers arranged at the rear section in the rotating shell (1) are pressed on the rear annular rail, the gear reduction motor (3) is arranged on the front rotating support frame (4), an annular gear is arranged at a position close to the front annular rail of the stainless steel rotating net (2), an output gear of the gear reduction motor (3) is meshed with the annular gear arranged on the stainless steel rotating net (2), an annular baffle is arranged in a rotary shell (1) close to the rear end of the stainless steel rotary net (2), a seawater pipe (6) is arranged at the bottom of the rotary shell (1) in front of the annular baffle, an outlet of the seawater pipe (6) is arranged above a seawater pool (8), a silt pool (7) is arranged below the rear end of the rotary shell (1), and dirty seawater is pumped to the front end of the stainless steel rotary net (2) from the sea by a dirty seawater pump; the rotary mesh tank consists of a mesh tank shell (13), a mesh tank sealing cover, a mesh tank sealing bottom, an outer stainless steel mesh clamp filter cloth pipe (14), an inner stainless steel mesh clamp filter cloth pipe (15), a mesh tank frame, a mesh tank central shaft, a mesh tank supporting frame (12) and a mesh tank motor (11), wherein the mesh tank frame is arranged in the mesh tank shell (13), the outer stainless steel mesh clamp filter cloth pipe (14), the inner stainless steel mesh clamp filter cloth pipe (15) and the mesh tank central shaft are sequentially arranged on the mesh tank frame from outside to inside, the upper end of the mesh tank central shaft penetrates through a mesh tank sealing cover central bearing and then is connected with a rotating shaft of the mesh tank frame motor (11) through a coupler, and the lower end of the mesh tank central shaft penetrates through the mesh tank sealing bottom central bearing; the net tank shell (13), the net tank sealing cover, the net tank sealing bottom and the net tank motor (11) are fixed on the net tank frame support frame (12); a plurality of turbine blades are arranged on the inner side of the outer stainless steel mesh clamp filter cloth pipe (14), and a plurality of turbine blades are arranged on the inner side of the inner stainless steel mesh clamp filter cloth pipe (15); a seawater inlet pipe is arranged on a mesh tank sealing cover between the mesh tank shell (13) and the outer stainless steel mesh clamp filtering cloth pipe (14), a seawater electric butterfly valve (10) is arranged on the seawater inlet pipe, and a seawater pump (9) extracts seawater from a seawater pool (8) and enters a space between the mesh tank shell (13) and the outer stainless steel mesh clamp filtering cloth pipe (14) through the seawater electric butterfly valve (10); a polymer purifying agent is filled in a mesh tank space between the outer stainless steel mesh clamp filtering cloth pipe (14) and the inner stainless steel mesh clamp filtering cloth pipe (15), a polymer water return pipe is arranged on a mesh tank sealing cover between the outer stainless steel mesh clamp filtering cloth pipe (14) and the inner stainless steel mesh clamp filtering cloth pipe (15), and a polymer water return electric butterfly valve (46) is arranged on the polymer water return pipe; algae water pipe (16) are equipped with on the net jar sealed bottom between net jar shell (13) and outer stainless steel net clamp filter cloth pipe (14), algae water electric butterfly valve (19) are equipped with on the algae water pipe, net jar sealed bottom between outer stainless steel net clamp filter cloth pipe (14) and interior stainless steel net clamp filter cloth pipe (15) is equipped with polymer water pipe (17), polymer water electric butterfly valve (20) are equipped with on polymer water pipe (17), net jar sealed bottom below interior stainless steel net clamp filter cloth pipe (15) is equipped with clean sea water pipe (18), export of clean sea water pipe (18) is in clean sea water pond (21) top, algae centrifuge's structure is similar with centrifugal sieve sugar machine's structure, algae centrifuge structure is as follows: the central shaft of the algae frame is fixed on the central line of the silt frame, the central shaft of the algae frame upwards passes through a central bearing of an algae sealing cover and then is connected with an algae motor (25) through a coupling, the algae motor (25) and the algae sealing cover are fixed on an algae supporting frame (30), the algae sealing cover is provided with an algae water pipe (16) outlet and an algae flushing water pipe outlet, an algae flushing electromagnetic water valve (23) is arranged on the algae flushing water pipe, a clean sea water pump (22) pumps clean sea water from a clean sea water pool (21), a branch water pipe connected from the clean sea water pump (22) is connected to the inlet of the algae flushing electromagnetic water valve (23), an algae stainless steel net clamping and filtering cloth pipe (26) is arranged on the side surface of the algae frame, one side of an algae sealing bottom (29) is fixed at one end of an algae lever, the other end of the algae lever is hinged with the lower end of the algae supporting frame (30), and the lower end of an algae longitudinal lever is hinged with the middle part of the algae lever, an algae control lever is sleeved with an algae tension spring (32), the upper end of the algae control lever is fixed on an armature of an algae electromagnet (31), and an algae pond (43) is arranged below an algae sealing bottom (29); the algae shell (27) covers the space between the algae sealed bottom and the algae sealed cover, a sealing ring is respectively arranged between the algae shell (27) and the algae sealed bottom (29) as well as the algae sealed cover, air blown by the algae blower (28) is blown out from a vertical gap on the algae shell (27), an algae filtered water collecting tank is arranged on the algae shell (27), and an algae filtered water collecting pipe (41) is arranged below the algae filtered water collecting tank; the structure of the polymer centrifugal separator is similar to that of a centrifugal sugar sieving machine, and the structure of the polymer centrifugal separator is as follows: a central shaft of the polymer rack is fixed on a central line of the polymer rack, the central shaft of the polymer rack upwards passes through a central bearing of a polymer sealing cover and then is connected with a shaft of a polymer motor (33) through a coupling, the polymer motor (33) and the polymer sealing cover are fixed on a polymer supporting frame (38), the polymer sealing cover is provided with a polymer water pipe (17) outlet, a water vapor pipe outlet and a polymer flushing water pipe outlet, water vapor generated by a boiler (47) enters a water vapor storage tank (49) through a water vapor one-way valve (48), and the water vapor in the water vapor storage tank (49) enters a polymer stainless steel mesh clamping and filtering cloth pipe (34) through a water vapor electromagnetic valve (50); a polymer flushing electromagnetic water valve (24) is arranged on the polymer flushing water pipe, a clean sea water pump (22) pumps clean sea water from a clean sea water pool (21), another branch water pipe connected from the clean sea water pump (22) is connected to an inlet of the polymer flushing electromagnetic water valve (24), a polymer stainless steel net clamping filter cloth pipe (34) is arranged on the side surface of the polymer rack, one side of a polymer sealing bottom (37) is fixed at one end of a polymer lever, the other end of the polymer lever is hinged with the lower end of a polymer supporting frame (38), the lower end of the polymer control lever is hinged with the middle of the polymer lever, a polymer tension spring (40) is sleeved on the polymer control lever, the upper end of the polymer control lever is fixed on a polymer electromagnet armature (39), and a polymer pool (44) is arranged below the polymer sealing bottom (37); the polymer shell (35) covers the space between the polymer sealing bottom (37) and the polymer sealing cover, a sealing ring is respectively arranged between the polymer shell and the polymer sealing bottom as well as between the polymer shell and the polymer sealing cover, air blown out by the polymer blower (36) is blown out from a vertical gap on the polymer shell (35), a polymer filtered water collecting tank is arranged on the polymer shell (35), a polymer filtered water collecting pipe (42) is arranged below the polymer filtered water collecting tank, the water outlet of the polymer filtered water collecting pipe (42) is arranged above the algae pond (43), and the algae water pump pumps the algae containing water in the algae pond to the mariculture fish pond; the water outlet of the algae filtered water collecting pipe (41) is arranged above the polymer pool, and the polymer water pump (45) pumps the regenerated polymer water in the polymer pool (42) out to enter a space between the outer stainless steel net clamp filter cloth pipe (14) and the inner stainless steel net clamp filter cloth pipe (15) of the rotary net tank through a polymer backwater electric butterfly valve (46).

2. The method according to claim 1, wherein the method further comprises: dirty seawater is pumped to the front end of the stainless steel rotating net (2) from the sea by a dirty seawater pump, the gear reduction motor (3) drives the stainless steel rotating net (2) to rotate, silt is left in the stainless steel rotating net (2), the seawater passes through the stainless steel rotating net (2) and flows to the bottom of the rotating shell (1), then flows to a seawater pool (8) from a seawater pipe (6), and the silt flows out of the rear end of the stainless steel rotating net (2) and flows into a silt pool (8) below the rear end of the rotating shell (1); the seawater pump (9) extracts seawater from the seawater pool (8), the seawater enters a space between the mesh tank shell (13) and the outer stainless steel mesh clamp filter cloth pipe (14) through the seawater electric butterfly valve (10), and algae are filtered out when the seawater passes through the outer stainless steel mesh clamp filter cloth pipe (14); the seawater containing small molecular organic matters enters a mesh tank space between an outer stainless steel mesh-sandwiched filter cloth pipe (14) and an inner stainless steel mesh-sandwiched filter cloth pipe (15) and is subjected to affinity with a polymer purifying agent; the seawater losing the small molecular organic matters passes through the inner stainless steel mesh clamp filter cloth pipe (15) to reach the inner stainless steel mesh clamp filter cloth pipe (15), and then flows from the clean seawater pipe (18) to the clean seawater pool (21); after the set time is reached, a large amount of algae are gathered at the outer side of the outer stainless steel mesh clamp filter cloth pipe (14), a large amount of polymer purifying agents are gathered at the outer side of the inner stainless steel mesh clamp filter cloth pipe (15), a polymer water return electric butterfly valve (46), a polymer water electric butterfly valve (20) and an algae water electric butterfly valve (19) are opened by a computer controller, a polymer water pump (45) and a mesh tank frame motor (11) are started, the mesh tank frame motor (11) rotates to drive a mesh tank central shaft, the inner stainless steel mesh clamp filter cloth pipe (15) and the outer stainless steel mesh clamp filter cloth pipe (14) to rotate, a plurality of turbine blades arranged at the inner side of the outer stainless steel mesh clamp filter cloth pipe (14) push seawater between the outer stainless steel mesh clamp filter cloth pipe (14) and the inner stainless steel mesh clamp filter cloth pipe (15) to penetrate through the outer stainless steel mesh clamp filter cloth pipe (14) to drive away the algae gathered at the outer side of the outer stainless steel mesh clamp filter cloth pipe (14), a plurality of turbine blades arranged on the inner side of the inner stainless steel mesh clamp filtering cloth pipe (15) push seawater in the inner stainless steel mesh clamp filtering cloth pipe (15) to pass through the inner stainless steel mesh clamp filtering cloth pipe (15) to drive away polymer purifying agents gathered on the outer side of the inner stainless steel mesh clamp filtering cloth pipe (15); seawater with high algae content between a mesh tank shell (13) and an outer stainless steel mesh clamp filtering cloth pipe (14) flows into an algae centrifugal separator through an opened algae water electric butterfly valve (19), a polymer water pump (45) pumps regenerated polymer water in a polymer pool (44) out to enter a space between the outer stainless steel mesh clamp filtering cloth pipe (14) and an inner stainless steel mesh clamp filtering cloth pipe (15) of a rotary mesh tank through a polymer water return electric butterfly valve (46), the seawater with high polymer micromolecule organic matter content between the outer stainless steel mesh clamp filtering cloth pipe (14) and the inner stainless steel mesh clamp filtering cloth pipe (15) flows into the polymer centrifugal separator through the opened polymer water electric butterfly valve (20), and after a set time is reached, a computer controller closes the polymer water return electric butterfly valve (46), the polymer electric butterfly valve (20) and the algae water electric butterfly valve (19), And stopping supplying power to the polymer water pump (45) and the driving motor (11), and rotating the net tank to produce clean seawater again, wherein the clean seawater flows into the clean seawater pool (21); the computer control instrument starts the algae motor (25), the algae motor (25) drives the algae stainless steel net clamp filtering cloth pipe (26) to rotate from slow to fast, seawater in the algae stainless steel net clamp filtering cloth pipe (26) is thrown out to an algae filtering water collecting tank of an algae shell (27), then the seawater flows into the polymer pool (44) from the algae filtering water collecting pipe (41), the algae motor (25) drives the algae stainless steel net clamp filtering cloth pipe (26) to rotate from fast to slow after the algae motor (25) rotates for a set time, the computer control instrument supplies power to the algae electromagnet (31), the algae washing electromagnetic water valve (23), the algae blower (28) and the clean seawater pump (22), the algae electromagnet (31) pushes down the algae control rod to drive the algae lever to rotate downwards to enable the algae sealing bottom (29) to rotate downwards, and wind blown by the algae blower (28) enters the algae shell (27) to enable algae attached to the inner surface of the algae stainless steel net clamp filtering cloth pipe (26) Class blowing, wherein a clean seawater pump (22) pumps clean seawater from a clean seawater pool (21) and sprays the clean seawater into an algae stainless steel net clamp filtering cloth pipe (26) through an algae washing electromagnetic water valve (23), and algae in the algae stainless steel net clamp filtering cloth pipe (26) is washed into an algae pool (43) by water sprayed by an algae washing water pipe; after the set time is reached, the computer control instrument stops supplying power to the algae motor (25), the algae electromagnet (31), the algae washing electromagnetic water valve (23) and the algae blower (28), the algae tension spring (32) pulls the algae control rod upwards, and the algae lever is driven to rotate upwards to close the algae sealing bottom (29) upwards; steam generated by a boiler (47) enters a steam storage tank (49) through a steam one-way valve (48), a computer control instrument starts a polymer motor (33), the polymer motor (33) drives a polymer stainless steel net clamp filtering cloth pipe (34) to rotate from slow to fast, polymer in the polymer stainless steel net clamp filtering cloth pipe (34) is separated from most of small molecular organic matters, seawater containing a large amount of small molecular organic matters is thrown out of the polymer stainless steel net clamp filtering cloth pipe (34) and into a polymer filtered water collecting tank of a polymer shell (35), then the seawater flows into an algae pond (43) from the polymer filtered water collecting pipe (34), after the polymer motor (33) rotates for a set time, the computer control instrument supplies power to a steam electromagnetic valve (50), the steam in the steam storage tank (49) enters the polymer stainless steel net clamp filtering cloth pipe (34) through the opened steam electromagnetic valve (50), separating residual polymer and micromolecular organic matters in the polymer stainless steel sandwich filter cloth pipe (34), throwing seawater containing a large amount of micromolecular organic matters out of the polymer stainless steel sandwich filter cloth pipe (34), throwing the seawater into a polymer filtered water collecting tank of a polymer shell (35), and then flowing into an algae pond (43) from a polymer filtered water collecting pipe (42); after the water vapor electromagnetic valve (50) is electrified for a set time, the computer controller stops supplying power to the water vapor electromagnetic valve (50), the polymer motor (33) drives the polymer stainless steel net clamp filter cloth pipe (34) to rotate from fast to slow, then the computer controller supplies power to the polymer electromagnet (39), the polymer flushing electromagnetic water valve (24) and the polymer blower (36), the polymer electromagnet (39) pushes the polymer control rod downwards, the polymer lever is driven to rotate downwards to enable the polymer sealing bottom (37) to rotate downwards, wind blown out by the polymer blower (33) enters the polymer shell (35) to blow away polymers attached to the inner surface of the polymer stainless steel net clamp filter cloth pipe (34), the clean sea water pump (22) extracts clean sea water from the clean sea water pool (21) and sprays the clean sea water into the polymer stainless steel net clamp filter cloth pipe (34) through the polymer flushing electromagnetic water valve (24), the polymer in the polymer stainless steel net clamping filter cloth pipe (34) is washed into a polymer pool (44) by the water sprayed by the polymer washing water pipe; after the set time is reached, the computer controller stops supplying power to the polymer motor (33), the polymer electromagnet (39), the polymer flushing electromagnetic water valve (24) and the polymer blower (36), the polymer control lever is pulled upwards by the polymer tension spring (40), and the polymer lever is driven to rotate upwards to close the polymer sealing bottom (37) upwards; the computer control instrument stops supplying power to the clean seawater pump (22), the computer control instrument starts the algae water pump, and the algae water pump pumps the water-containing algae in the algae pond to the mariculture fishpond.

3. A seawater pretreatment device used in seawater desalination is characterized in that: the seawater pretreatment equipment consists of a stainless steel rotary screen silt screening machine, a rotary ceramic tank, an algae centrifugal separator, a foamed ceramic evaporator and a delivery pump, and is controlled by a computer controller; the stainless steel rotating net silt screening machine is made of a rotating shell (1), a stainless steel rotating net (2), a gear reduction motor (3) and a rotating support frame, wherein the rotating shell (1) is obliquely arranged on a front rotating support frame (4) and a rear rotating support frame (5) in a high-back low-back manner, a front annular rail is arranged at a position close to the front end of the stainless steel rotating net (2), three front rollers arranged at the front section in the rotating shell (1) are pressed on the front annular rail, a rear annular rail is arranged at a position close to the rear end of the stainless steel rotating net (2), three rear rollers arranged at the rear section in the rotating shell (1) are pressed on the rear annular rail, the gear reduction motor (3) is arranged on the front rotating support frame (4), an annular gear is arranged at a position close to the front annular rail of the stainless steel rotating net (2), an output gear of the gear reduction motor (3) is meshed with the annular gear arranged on the stainless steel rotating net (2), an annular baffle is arranged in a rotary shell (1) close to the rear end of the stainless steel rotary net (2), a seawater pipe (6) is arranged at the bottom of the rotary shell (1) in front of the annular baffle, an outlet of the seawater pipe (6) is arranged above a seawater pool (8), a silt pool (7) is arranged below the rear end of the rotary shell (1), and dirty seawater is pumped to the front end of the stainless steel rotary net (2) from the sea by a dirty seawater pump; the rotary ceramic tank consists of a ceramic tank shell (13 '), a ceramic tank sealing cover, a ceramic tank sealing bottom, an outer foam ceramic tube (14 '), an inner foam ceramic tube (15 '), a ceramic tank frame, a ceramic tank central shaft, a ceramic tank supporting frame (12 ') and a ceramic tank motor (11 '), wherein a plurality of inclined scraping blades are arranged on the inner surface of the ceramic tank shell (13 '), the outer foam ceramic tube (14 '), the inner foam ceramic tube (15 ') and the ceramic tank central shaft are sequentially arranged on the ceramic tank frame from outside to inside, the upper end of the ceramic tank central shaft penetrates through a central bearing of the ceramic tank sealing cover and then is connected with a rotating shaft of the ceramic tank motor (11 ') through a coupler, and the lower end of the ceramic tank central shaft penetrates through the central bearing of the ceramic tank sealing bottom; the ceramic pot shell (13 '), the ceramic pot sealing cover, the ceramic pot sealing bottom and the ceramic pot motor (11 ') are fixed on the ceramic pot frame support frame (12 '); a seawater inlet pipe is arranged on a ceramic tank sealing cover between the ceramic tank shell (13 ') and the outer foam ceramic pipe (14'), a seawater electric butterfly valve (10) is arranged on the seawater inlet pipe, and a seawater pump (9) extracts seawater from a seawater pool (8) and enters a space between the ceramic tank shell (13 ') and the outer foam ceramic pipe (14') through the seawater electric butterfly valve (10); a polymer purifying agent is filled in a ceramic tank space between the outer foamed ceramic tube (14 ') and the inner foamed ceramic tube (15'), and a polymer return tube is arranged on a ceramic tank sealing cover between the outer foamed ceramic tube (14 ') and the inner foamed ceramic tube (15'); an algae water pipe (16) is arranged on a ceramic tank sealing bottom between a ceramic tank shell (13 ') and an outer foam ceramic pipe (14'), an algae water electric butterfly valve (19) is arranged on the algae water pipe (16), a polymer outlet pipe (17 ') is arranged on the ceramic tank sealing bottom between the outer foam ceramic pipe (14') and an inner foam ceramic pipe (15 '), a polymer outlet electric butterfly valve (20') is arranged on the polymer outlet pipe (17 '), a clean seawater pipe (18) is arranged on the ceramic tank sealing bottom below the inner foam ceramic pipe (15'), the outlet of the clean seawater pipe (18) is arranged above a clean seawater pool (21), the structure of the algae centrifugal separator is similar to that of a centrifugal sugar screening machine, and the structure of the algae centrifugal separator is as follows: the central shaft of the algae frame is fixed on the central line of the silt frame, the central shaft of the algae frame upwards passes through a central bearing of an algae sealing cover and then is connected with an algae motor (25) through a coupling, the algae motor (25) and the algae sealing cover are fixed on an algae supporting frame (30), the algae sealing cover is provided with an algae water pipe (16) outlet and an algae flushing water pipe outlet, an algae flushing electromagnetic water valve (23) is arranged on the algae flushing water pipe, a clean sea water pump (22) pumps clean sea water from a clean sea water pool (21), a branch water pipe connected from the clean sea water pump (22) is connected to the inlet of the algae flushing electromagnetic water valve (23), an algae stainless steel net clamping and filtering cloth pipe (26) is arranged on the side surface of the algae frame, one side of an algae sealing bottom (29) is fixed at one end of an algae lever, the other end of the algae lever is hinged with the lower end of the algae supporting frame (30), and the lower end of an algae longitudinal lever is hinged with the middle part of the algae lever, an algae control lever is sleeved with an algae tension spring (32), the upper end of the algae control lever is fixed on an armature of an algae electromagnet (31), and an algae pond (43) is arranged below an algae sealing bottom (29); the algae shell (27) covers the space between the algae sealed bottom and the algae sealed cover, a sealing ring is respectively arranged between the algae shell (27) and the algae sealed bottom (29) as well as the algae sealed cover, air blown out by the algae blower (28) is blown out from a vertical gap on the algae shell (27), an algae filtered water collecting tank is arranged on the algae shell (27), an algae filtered water collecting pipe (41) is arranged below the algae filtered water collecting tank, and the water outlet of the algae filtered water collecting pipe (41) is arranged above the algae filtered water tank (44'); a pipeline connected with the algae filtering water pump (45 ') is converged with the seawater pipe through an algae filtering backwater electromagnetic valve (46'); a pipeline from the polymer outlet pipe (17 ') passes through a polymer outlet electric butterfly valve (20'), then is movably connected with the left end of a foamed ceramic evaporation pipe (34 ') of a foamed ceramic evaporator through a sealing ring, the right end of the foamed ceramic evaporation pipe (34') of the foamed ceramic evaporator is movably connected with a left connector of a tee joint through the sealing ring, a temperature sensor probe is arranged in the left connector of the tee joint, an evaporator motor (35 ') drives the foamed ceramic evaporation pipe (34') of the foamed ceramic evaporator to rotate through a gear, and a fuel oil burner (35 ') is arranged below the rear section of the foamed ceramic evaporation pipe (34') of the foamed ceramic evaporator; an oil pipe connected from the bottom of the fuel tank (47 ') is connected to an inlet of a fuel pump (48'), the oil pipe connected from an outlet of the fuel pump (48 ') is connected to an inlet of a nozzle of a fuel burner (35') through an electric fuel regulating valve (49 '), and an air pipe connected from a fuel blower (50') is connected to the fuel burner (35 ') through an electric regulating air valve (51'); an air outlet pipeline of an air compressor (37 ') is connected to the top of an air storage tank (39') through a one-way air valve (38 '), a compressed air pressure sensor is arranged at the top of the air storage tank (39'), an air pipe connected from the bottom of the air storage tank (39 ') is connected to the top of a polymer tank (42') through a compressed air solenoid valve (40 '), a polymer pressure sensor is arranged at the top of the polymer tank (42'), a polymer purifying agent is arranged in the polymer tank (42 '), a tee joint connected with a pipeline connected from the bottom of the polymer tank (42') is connected with an inlet of a screw extrusion pump (36 '), and an outlet of the screw extrusion pump (36') is connected with an inlet of a polymer return pipe.

4. The method according to claim 3, wherein the seawater pretreatment apparatus comprises: dirty seawater is pumped to the front end of the stainless steel rotating net (2) from the sea by a dirty seawater pump, the gear reduction motor (3) drives the stainless steel rotating net (2) to rotate, silt is left in the stainless steel rotating net (2), the seawater passes through the stainless steel rotating net (2) and flows to the bottom of the rotating shell (1), then flows to a seawater pool (8) from a seawater pipe (6), and the silt flows out of the rear end of the stainless steel rotating net (2) and flows into a silt pool (8) below the rear end of the rotating shell (1); a seawater pump (9) pumps seawater from a seawater pool (8) and enters a space between a ceramic tank shell (13 ') and an outer foam ceramic pipe (14 ') through a seawater electric butterfly valve (10), and algae are filtered out when the seawater passes through the outer foam ceramic pipe (14 '); seawater containing small molecular organic matters enters a ceramic tank space between an outer foamed ceramic tube (14 ') and an inner foamed ceramic tube (15') and is subjected to affinity with a polymer purifying agent; the seawater without small molecular organic matters passes through the inner foam ceramic pipe (15 ') to reach the inner foam ceramic pipe (15'), and then flows to a clean seawater pool (21) from a clean seawater pipe (18); a large amount of algae are gathered at the outer side of the outer foam ceramic pipe (14 '), the computer controller opens the polymer outlet electric butterfly valve (20'), the algae water electric butterfly valve (19) and starts the ceramic irrigation motor (11 '), the ceramic tank motor (11') rotates to drive the central shaft of the ceramic tank, the inner foam ceramic pipe (15 ') and the outer foam ceramic pipe (14') to rotate, algae at the outer side of the outer foam ceramic pipe (14 ') are scraped by a scraper on the inner surface of the ceramic tank shell (13') and then transferred into the algae water pipe (16), and then enter the algae centrifugal separator through the opened algae water electric butterfly valve (19); the computer control instrument starts the algae motor (25), the algae motor (25) drives the algae stainless steel net clamp filtering cloth pipe (26) to rotate from slow to fast, seawater in the algae stainless steel net clamp filtering cloth pipe (26) is thrown out to an algae filtered water collecting tank of an algae shell (27), then the seawater flows into an algae filtering water collecting tank (44 ') from the algae filtered water collecting pipe (41), the algae motor (25) drives the algae stainless steel net clamp filtering cloth pipe (26) to rotate from fast to slow after the algae motor (25) rotates for a set time, the computer control instrument supplies power to the algae electromagnet (31), the algae washing electromagnetic water valve (23), the algae blower (28) and the sea water purification pump (22), the algae electromagnet (31) pushes down the algae control rod to drive the algae lever to rotate downwards to enable the algae sealing bottom (29) to rotate downwards, and air blown out by the algae blower (28) enters the algae shell (27) to drive the inner surface of the algae stainless steel net clamp filtering cloth pipe (26) to rotate from slow to fast according to the algae filtering cloth pipe, and the seawater in the water collecting tank (44') is filtered by the algae filtering cloth pipe, and the algae filtering cloth pipe (26) is cleaned by the algae motor (25), and the algae motor (25) drives the algae motor (25) to rotate from fast, so that the algae filtering cloth pipe (25) to rotate from fast, the algae filtering cloth pipe (26) to rotate from fast, the algae filtered water collecting tank (25) to rotate from fast, the algae filtering cloth pipe (26) to rotate from fast to rotate to slow to rotate so that the algae washing electromagnetic motor (22) and the algae washing electromagnetic motor (25) and the algae to rotate so that the algae can be cleaned water can be cleaned so as to be cleaned water can be cleaned so as to be cleaned so as The algae is blown away, a clean seawater pump (22) pumps clean seawater from a clean seawater pool (21) and sprays the clean seawater into an algae stainless steel net clamp filtering cloth pipe (26) through an algae flushing electromagnetic water valve (23), and the algae in the algae stainless steel net clamp filtering cloth pipe (26) is flushed into an algae pool (43) by water sprayed by an algae flushing water pipe; after the set time is reached, the computer control instrument stops supplying power to the algae motor (25), the algae electromagnet (31), the algae washing electromagnetic water valve (23) and the algae blower (28), the algae tension spring (32) pulls the algae control rod upwards, and the algae lever is driven to rotate upwards to close the algae sealing bottom (29) upwards; the algae filtering water pump (45 ') pumps algae filtering water from the algae filtering water pool (44 ') and enters a seawater pipe through the opened algae filtering water return electromagnetic valve (46 '), and the algae filtering water enters a space between the ceramic tank shell (13 ') and the outer foam ceramic pipe (14 ') after being gathered with seawater in the seawater pipe; the computer controller starts the air compressor (37 '), compressed air from the air compressor (37 ') enters the air storage tank (39 ') through the one-way air valve (38 '), when the compressed air pressure sensor detects that the pressure of the air storage tank (39 ') reaches a set high air pressure, the computer controller stops supplying power to the air compressor (37 '), the one-way air valve (38 ') can prevent the compressed air in the air storage tank (39 ') from leaking out of the air compressor (37 '), and when the compressed air pressure sensor detects that the pressure of the air storage tank (39 ') is lower than a set low air pressure, the computer controller restarts the air compressor (37 '); the compressed air from the bottom of the air storage tank (39 ') enters the top of the polymer tank (42 ') through the opened compressed air solenoid valve (40 '), when the polymer pressure sensor detects that the pressure of the polymer tank (42 ') reaches the set high pressure, the computer control instrument closes the compressed air solenoid valve (40 '), and when the polymer pressure sensor detects that the pressure of the polymer tank (42 ') is lower than the set low pressure, the computer control instrument reopens the compressed air solenoid valve (40 '); the polymer depurative circulating system is pressurized by the polymer depurative with certain pressure in the polymer tank (42') so as to reduce excessive seawater from remaining in the polymer depurative; starting a screw extrusion pump (36 '), wherein the screw extrusion pump (36 ') extracts a planning document and a reagent from a polymer tank (42 ') and a foamed ceramic evaporation pipe (34 ') of the foamed ceramic evaporator, then the planning document and the reagent are conveyed into a gap between an outer foamed ceramic pipe (14 ') and an inner foamed ceramic pipe (15 ') through a polymer return pipe, a polymer purifying agent which is in the gap between the outer foamed ceramic pipe (14 ') and the inner foamed ceramic pipe (15 ') and has affinity with small molecular organic matters is extruded from a polymer outlet pipe (17 ') arranged on a sealing bottom of the ceramic tank, and the polymer purifying agent enters the foamed ceramic evaporation pipe (34 ') of the foamed ceramic evaporator through an opened polymer outlet electric butterfly valve (20 ') to form circulation; in the front section of a foamed ceramic evaporation pipe (34 ') of the foamed ceramic evaporator, seawater in the polymer purifying agent is extruded to flow out from the pores of the foamed ceramic evaporation pipe (34') of the foamed ceramic evaporator; the computer control instrument starts a fuel pump (48 '), fuel oil from the bottom of a fuel tank (47 ') enters the fuel pump (48 '), the fuel oil from the fuel pump (48 ') enters a fuel oil burner (35 ') through a fuel oil electric regulating valve (49 '), is ignited after being sprayed out from a nozzle of the fuel oil burner (35 '), and air blown out from a fuel oil blower (50 ') enters the fuel oil burner (35 ') through an electric regulating air valve (51 ') to support the combustion of the fuel oil burner (35 '); the computer controller starts an evaporator motor (35 '), the evaporator motor (35') drives a foamed ceramic evaporation tube (34 ') of the foamed ceramic evaporator to rotate through a gear, and a flame burnt by an oil burner (35') below the rear section of the foamed ceramic evaporation tube (34 ') of the foamed ceramic evaporator uniformly heats a polymer purifying agent containing a large amount of small-molecular organic matters in the rear section of the foamed ceramic evaporation tube (34') of the foamed ceramic evaporator; after the set temperature is reached, the micromolecular organic matters in the rear section of the foamed ceramic evaporation tube (34 ') of the foamed ceramic evaporator are evaporated into gas which escapes from micropores in the rear section of the foamed ceramic evaporation tube (34') of the foamed ceramic evaporator; the temperature sensor probe arranged in the left interface of the tee joint detects that the temperature of the polymer purifying agent coming out of the foamed ceramic evaporation tube (34 ') of the foamed ceramic evaporator reaches a set high temperature, and the computer controller reduces the fuel electric regulating valve (49 ') and the electric regulating air valve (51 ') so as to reduce the thermal power output by the fuel burner (35 ') and reduce the temperature of the polymer purifying agent in the foamed ceramic evaporation tube (34 ') of the foamed ceramic evaporator; the temperature sensor probe arranged in the left interface of the tee joint detects that the temperature of the polymer purifying agent coming out of the foamed ceramic evaporation tube (34 ') of the foamed ceramic evaporator is lower than the set low temperature, and the computer controller increases the fuel electric regulating valve (49 ') and the electric regulating air valve (51 ') so as to increase the thermal power output by the fuel burner (35 ') and increase the temperature of the polymer purifying agent in the foamed ceramic evaporation tube (34 ') of the foamed ceramic evaporator.