161 results about "Industrial culture" patented technology

The invention relates to a method for high-density industrial culture of blood-sucking leeches, which belongs to the technical field of artificial culture of the blood-sucking leeches. The culture method cultures commercial leeches artificially by the steps of selecting a place, building a pond, putting leech seeds into the pond, feeding the leech seeds, preparing cocoon producing beds, producing cocoons and hatching the cocoons, culturing young leeches, living through the winter and the like, and achieves recirculation culture by the steps of producing the cocoons and hatching the cocoons. In the culture process, when the reproduction rate of the cultured leeches goes down after three generations of close breeding, the cultured leeches are mated with wild leeches to achieve the aim of the rejuvenescence of parent leeches. The culture method solves the problems that the changes of the natural environment and the increment of pollutant sources make naturally-growing leech sources decrease day by day and the gradually expanded market demand cannot be satisfied. The culture method for culturing the leeches has less investment but high production. The input of 100 kilograms of the leeches can yield 200 kilograms of the commercial leeches. The culture method can culture the leeches not only by building large vinyl tunnels and ponds, but also by using rural homesteads, yards or vacant houses for building the ponds, and has good economic benefits.

The invention provides a method for industrialized cultivation of Cordyceps militaris with high content of cordycepin. The method of the present invention uses the screened bacterial strains Cordyceps militaris COB201 and CGMCC No.1823 to carry out optimized cultivation to obtain Cordycepin militaris with a high content of cordycepin. The content of cordycepin in the product reaches 1.7% after testing. The method of the present invention is simple and suitable for large-scale industrialization Production.

The invention provides a formula of a culture medium for industrial production of sparasis crispa and a production process. The formula of the culture medium comprises the following components in percentage by dry weight: 65 to 75 percent of pine sawdust, 10 to 20 percent of husk, 5 to 10 percent of potato powder, 5 to 10 percent of flour, 0.1 to 0.5 percent of peptone, 0.1 percent of ammonium sulfate and 1.2 to 1.8 percent of brown sugar. The production process comprises the following steps of: preparing and bagging the culture medium; sterilizing and inoculating; culturing hypha; inducing a primodium; differentiating the primodium; opening the bag; managing balls; and harvesting. The invention provides a formula of a culture medium for industrial production of sparasis crispa, which has the advantages of rich nutrition, balanced proportion, good ventilation, and capacity of meeting the requirement of industrial production. The production process has the advantages of short hypha culturing time, uniform fruiting at bag openings, good fruiting consistency, convenience of management, contribution to industrial culture, white mushroom body, high yield, and high biological transformation rate of over 43 percent.

The invention relates to an integral indoor ecological circulating water culture system, belonging to the technical field of culture water biological purification. The system comprises a vinyl house, a sedimentation basin, a methane tank, a biological filter pool A, a biological filter pool B, a biological filter pool C, a water storage tank, a breeding pond A, a breeding pond B, a breeding pond C, a breeding pond D and a breeding pond E, and wherein the sedimentation basin, the biological filter pools, the water storage tank, and the breeding ponds are symmetrically arranged in the vinyl house in a straight line. A water collecting main pipe, a back-flow pipe and an aeration main pipe are sequentially arranged on two sides of the sedimentation basin, the biological filter pools, the water storage tank and the breeding ponds. After being processed by multiple steps such as automatic collection and sedimentation, filtration, and absorption and conversion by water plant and stuffing materials, the breeding water of the system enters into the water storage tank to be subjected to reoxygenation and sterilization, then the breeding water is promoted into the breeding ponds for circulation and utilization through an immersible pump, thus the production cost of indoor industrial culture is lowered, and the system has remarkable popularization and application prospect in water shortage areas in our country for developing the high-density culture.

The invention discloses an ecotype enclosed method for culturing fish through circulation water. Natural seawater, underground salt water, underground fresh water and geothermal water are mainly utilized and mixed, and an industrial culture foundation for producing pollution-free healthy seafood is built and used. A solid-liquid separation purification device is used for replacing sand filtration of a biological filter, ammonia nitrogen and nitrite nitrogen are degraded after water passing through a biological film on biological filler in the biological filter, and the total purification rate of water body particles is over 99%. An aeration pond is arranged to conduct aeration and oxygenation on a culture water body to enable the content of dissolved oxygen in water in a fish culture pond to be kept at 8-14mg / L, finally the water body is sterilized through ultraviolet light, clean ecological water is input into the fish culture pond, and the return water in the fish culture pond is purified repeatedly and utilized in a circulating mode. Sewage discharged from a culture system is purified by an open-air pond and flows back to a water storage sedimentation pond to achieve zero-discharge complete enclosed circulation water factory-like fish culture.

The invention discloses a preparation method for a sludge aerobic composting composite inoculums. According to the method, the Bacillus subtilis (No. 10066), the Bacillus licheniformis (No. 10103), the Lactobacillus acidophilus (No. 6075), the Candida utilis (No. 31272), and the Phanerochaete chrysosporium (No. 40719) that are preserved in China Center of Industrial Culture Collection (CICC) are subjected to individual culture, and are then mixed in proportion and inoculated into a fermentation culture to perform expanded culture, thus obtaining the composite inoculum. At the initial stage of inoculating the composite inoculums to sludge aerobic composting, the time for the compost body to reach a high temperature period is advanced by 4-6 days, the compositing period is shortened by 11-14 days, the stack moisture content is decreased by 18%-25%, and the total nitrogen content of the compost body is increased by 15%-20%, thus improving the composting effect.

The invention discloses a leech industrial soilless three-dimensional high-efficiency culture method. The leech industrial soilless three-dimensional high-efficiency culture method comprises the following steps of: a, building an industrial culture pond; b, cocoon production; c, incubation; d, larva culture; e, larva stocking; f, culture management; and g, finished product leech harvest, wherein multi-edge multi-angle three-dimensional environments are created in the culture pond; artificial soilless three-dimensional caves are provided; and a first-level platform, a second-level platform, a third-level platform and a deepwater region are provided. By the leech industrial soilless three-dimensional high-efficiency culture method, cost can be saved; the leech is wide-body golden-thread leech and the survival rate of the larvae reaches over 95 percent; the growth time is about 90 days from the larvae to the finished products and the growth time in the natural world is 180 days; density is increased due to three-dimensional culture; and the finished products can be cleaned and harvested conveniently.

The invention belongs to the field of microalgae culture, and particularly relates to an inserting-plate type microalgae semi-dry solid adherent culture device. The inserting-plate type microalgae semi-dry solid adherent culture device is characterized by comprising a supporting truss, culture plates, liquid distributing pipes, liquid collecting tanks and a liquid storage bottle, wherein the supporting truss is provided with at least one culture plate, and one liquid distributing pipe is arranged above each culture plate; the liquid collecting tank arranged on the supporting truss is arranged under each culture plate; all the liquid collecting tanks are communicated with the liquid storage bottle by the main liquid pipe; the bottom of the liquid storage bottle is respectively provided with a circulating pump and a carbon-supplementing gas distributing pipe communicated with a carbon dioxide source, and the circulating pump is communicated with a liquid distributing pipe by a pipeline; and each culture plate is provided with a picking scraper. The inserting-plate type microalgae semi-dry solid adherent culture device has the advantages that the yield in unit occupied area is effectively increased, the culture period is shortened, the water consumption for culture is greatly reduced, the cost and the operating cost of the culture device are reduced and the industrial culture on large scale is easily realized.

The invention discloses a high-density fermenting method of bacillus coagulans for livestock and poultry, as well as a preparation prepared by the method and application thereof. The strain collection number of the bacillus coagulans is CICC (China Center of Industrial Culture Collection) No.20138. The method comprises the following steps: performing liquid fermentation on the bacillus coagulans;performing solid alternating temperature continuous fermentation; ventilating in later phase of solid fermentation; continuing fermenting and drying, and preparing a bacillus coagulans preparation initial product after the drying is completed; further crushing and screening to obtain a high-density bacillus coagulans preparation final product, wherein the number of strains of the final product is115.5*10<8>cfu.g<-1>, and the spore rate is 77.2%. The product has the effects of increasing the weight and preventing diarrhea of piglet, and the application adding concentration is 0.05wt%. The number of strain preparation is far higher than that of similar strain preparations (20*10<8>cfu.g<-1>) in the market, so that the preparation has wide market competitively in the livestock and poultry breeding industry.

The invention provides a new technological method for preparing and industrially culturing aweto strains. The method comprises the following steps of: using young silkworms of 2 years as a host of an aweto culture medium, preparing strains by separating the tissue of wild awetos, dying the young silkworms, providing biological conditions suitable for aweto growth, and culturing aweto products with the shapes of wild awetos and the similar contents of various food mass. The invention has simple and convenient operation process, high yield rate and low culture cost.

Disclosed is a method for tissue culture of rhododendron. The tissue culture method comprises the steps that: step 1: rhododendron explant material is collected, and placed on a supper-clean bench after being treated; the rhododendron explant material is disinfected by alcohol with a concentration of 75 percent for 6 to 8 seconds, washed by sterile water for three times, disinfected by 0.001 litre of mercury for 6 to 8 minutes, and washed by sterile water for three times in order; step 2: the material after being disinfected and cut is implanted into bud induce culture medium for thirty days; 30 days later, the obtained material is then implanted into proliferation culture medium for 60 days; step 3: healthy and strong rhododendron seedlings cut with 2 to 3cm by height are implanted into a rooting culture medium for 45 days; step 4: after the newborn root of rhododendron is about 0.5 cm long, the culture medium attached to the root is cleaned and newborn root is moved into sterile thick sand, the air humidity of which is kept ranging from 75 percent to 85 percent; one week later, the newborn root is moved into the mixed material of turfy soil and perlite; 45 days later, the treated root is moved into the field where the root is under the shade for one week. The method can realize industrial culture of seedling within 6 to 7 mouths and mass production of shipshape nursery stock of rhododendron.

An industrial culture method for prawn includes such steps as arranging the serially connected high-level culture pool and low-level culture pool, culturing the young prawn in the high-level culture pool for 30-50 days, and culturing in the low-level culture pool. Its culture pool system is composed of a primary high-level culture pool, a secondary low-level culture pool, transfer pipeline, and two drain pipes. It can output prawn three times in one year.

The invention discloses an indoor industrial culture method for portunus trituberculatus, comprising the following steps of: building a culture bond, preparing culture baskets, shelving the culture baskets, stocking crab seedlings, managing culture and directionally mating. A horizontal shelf is arranged in the culture bond, a long-edge basket of the culture baskets is equipped with a slot in which a separation plate is inserted, a hiding room containing silt is arranged in the culture baskets on the left side and the right side of the separation plate, and male and female crab seedlings are independently cultured in the culture baskets on the left side and the right side of the separation plate; after growth shelling and reproduction shelling, the separation plate is taken off so that one male portunus trituberculatus and one female portunus trituberculatus naturally mate in the culture baskets, and after mating, the male portunus trituberculatus is moved out of the culture basket atonce. The indoor industrial culture method for the portunus trituberculatus has the advantages of easy control on water quality, high survival rate and good culture benefit, and can prevent the portunus trituberculatus from killing each other, and the portunus trituberculatus is not injured by wind damages and wave damages.

The invention relates to a method for breeding rice field eels at high density in flowing water under controlled-temperature condition, which belongs to the technical field of fishery science application, and is characterized in that: a flowing water culture pool is built in a fully-closed greenhouse, and strong rice field eel fry are selected; fry are added according to a density of 5 to 6kg / m<2>; the fed feed is the mixture of commercial rice field eel compound feed and fresh silver carp flesh; the daily additive amount of feed is 4 to 6 percent based on the weight of the rice field eels; and micro flowing water is kept in the flowing water culture pool, the flow rate is kept between 0.05 and 0.10m<3> / h, and the water temperature of the flowing water culture pool is kept between 25 and 28 DEG C. In the invention, the large-scale soilless flowing water culture pool is built, an in-greenhouse controlled-temperature culture mode has the advantages of fresh culture water with rich dissolved oxygen, high culture density, and high feeding drive and growth speed and few diseases of the rice field eels and is an industrial culture mode; and compared with the prior pool net cage culture mode, the culture mode has higher per unit area yield and greater economic benefit.

The invention relates to a production method for a high-purity galacto-oligosaccharide. A galacto-oligosaccharide fermentation broth is prepared by a ten-bed continuous simulated moving bed chromatography separation after ceramic membrane ultrafiltration and ion exchange treatment. The product has a purity of more than 95%, a complete separation of monosaccharide and lactose in a galacto-oligosaccharide solution is well realized with high separation efficiency, and the quality of the product is further improved. The bacterial strain of aspergillus oryzae BLB-21 applied by the product process is preserved in China Center of Industrial Culture Collection on 17th Martch, 2009, with a preservation number of CGMCC No. 2951.

The invention discloses vegetable soil free culture of seedling nutrition master agent, and relates to the technical improvement on vegetable culture of seedling, in particular to a preparation for comprehensive nutrition master agent used for preparing the substrate of vegetable soil free culture of seedling, and belongs to the field of agriculturally industrial culture of seeding. The invention provides the vegetable soil free culture of the seedling nutrition master agent without concentration obstacle and being capable of continuously fertilizer feeding and simplifying the culture of seeding procedure. The invention comprises primary substrate which combines grass carbon and vermiculite with volume proportion of 2:1. The invention is characterized in that the primary substrate of each cubic meter comprises 1.5 to 2. 5 kg of lemery type composite fertilizer, 10 to 15 g of fulvic acid, and 8 to 10 kg of zeolete sorbent, which are mixed evenly.

The invention discloses a method for culturing industrial liquorice cells, and belongs to the liquorice cell culture technology. The method comprises the steps of inoculating liquorice seeds in an MS culture medium after sterilization for inducing aseptic sprouts of the liquorice; transferring cut liquorice sprout segments to a callus culture medium for solid culture so as to generate a liquorice callus; transferring the callus to a cell culture medium for suspension culture and then subculture so as to obtain liquorice cell sap with stable cell output; and transferring the liquorice cell sap to a stirring paddle type reactor for scale suspension culture of the liquorice cells to obtain liquorice cell suspension with cell output of 15-40g / l by cell dry weight. The method is characterized by simple process, quick cell growth, stable output, etc.

The invention relates to a bag-cultivation industrial culture process for golden mushrooms in China, and an optimization, regulation and control technology is adopted for the environment temperature, the environment humidity and the air concentration which are required for the growth and the development of the golden mushrooms. On the basis of the prior golden mushroom industrial culture conditions, and by changing the cold air flow direction and the air speed of an air cooler, the cold air cannot directly blow to a fungus pack on the top bed; three axial fans are additionally arranged indoors to form an indoor air internal circulation system; the facilities are optimized, regulated and controlled, a circular ventilation opening is arranged on the wall facing to the center at the rear part of the air cooler, and an air throttle for controlling the opening and the closing is installed at the outer side; microcomputer time controllers are installed for a fan and a ventilation fan, the start-stop time is set according to the parametric variation rules in different stages of growth and development of the golden mushrooms, and the operating time of the internal circulation system is controlled.

The invention discloses a material feeding machine for edible fungi industrial culture. The material feeding machine is characterized by consisting of a perpendicular lifting device, a conveying device (2), a material pressing device (4), a thickness determining device (5) and a material throwing device (6), wherein the material pressing device (4), the thickness determining device (5) and the material throwing device (6) are arranged on a working surface of the conveying device (2) and are horizontally arranged in tandem, and the conveying device (2) is arranged on the lower side, so that a material feeding machine combined working body is formed; the material feeding machine combined working body is arranged on a frame body (1); each functional unit synchronously continues the work of an upper unit and a lower unit while completing emphasized tasks, so that equipment has relatively high comprehensive usability and high efficiency as well as multiple functions; multiple steps of work can be finished on the same equipment; and the material feeding machine is high-efficiency, stable and practical special culture mechanical equipment.

The invention belongs to the technical field of animal manure comprehensive utilization and culture, and relates to a method for culturing maggot by utilizing livestock and poultry manure slurry. The method comprises the following steps: collecting animal manure in a temporary animal manure lagoon; fermenting effective microorganism (EM) strain, or enzymatic microorganism, or mixed strains of the EM strain and the enzymatic microorganism to ensure that the manure slurry is liquefied to form liquefied manure slurry; putting putrescent food in an outdoor fly concentrated position; putting collected seed maggot on a net chain above a fly cage to collect fly eggs and maggot; and maintaining the temperature of diluted manure slurry in a maggot culture pond, introducing oxygen to ensure that the maggot is cultured for 3 to 4 days and developed into imagochrysalis, and capturing by utilizing a net bag. The culture process has the advantaages of simple process, high animal manure utilization, safe and reliable equipment, high maggot culture benefit, large comprehensive utilization value, high quality of maggot and light environmental pollution, and can be used for large-scale industrial culture.

The present invention relates to a method for culturing microalgae by using coking wastewater, wherein a proper amount of coking wastewater is added to a microalgae culture medium, and the microalgae cells are cultured until achieving a stable growth stage so as to harvest the microalgae. According to the present invention, the results show that the growth rate of the microalgae in seawater added with the coking wastewater is higher than the growth rate of the microalgae only in seawater, and the total nitrogen of the coking wastewater is effectively degraded; and the microalgae culture and the coking wastewater treatment are combined, such that the microalgae production cost can be effectively reduced, the coking wastewater treatment environmental benefits are achieved while the microalgae is cultured, the microalgae industrial culture cost is easily reduced, and the algae bio-energy industrialization is promoted.

The invention relates to pullulanase and a production method thereof, and belongs to an amylolytic enzyme acted on an alpha-1,6-glucosidic bond. The pullulanase and the production method are characterized in that: a, zymologic characteristic is that the optimal pH is 3.8 to 4.4, the stable pH is 3.5 to 4.5, and the optimal action temperature is 50 to 65 DEG C; and b, Bacillus licheniformis is selected as an enzyme producing strain and derived from China Center of Industrial Culture Collection (CICC No.10185), and the pullulanase is prepared by a liquid state fermentation process in a mode of compositely feeding a backing material and a feed supplement and the method meets the following technological indexes that: (1) the enzymatic activity of the product is more than or equal to 1,100u / ml; (2) the fermentation period is 72 to 80 hours; and (3) the liquid enzyme recovery rate is more than or equal to 86.5 percent. The pullulanase product has the advantages of high heat resistance and acid resistance, high enzymatic activity, stable performance and low cost; the liquid biological fermentation production method has the advantages of high fermentation enzymatic activity, high extracting yield and low manufacturing cost; and the pullulanase and the production method are suitable for the fermentation industry using starch as a raw material and manufacturing of modified starch products, amylose starch and high-amylose starch.

The invention relates to an acidic proteinase and a preparation method thereof and the acidic proteinase belongs to the microbial acidic proteinase. The invention is characterized in that 1) the enzymatic characteristics of the acidic proteinase are as follows: the optimum pH value is 2.5-3.5, the stable pH value is 2.5-6.0; the optimum temperature is 40-50 DEG C, the temperature stability range is 30-50 DEG C; and 2) the preparation method uses Aspergillus Niger which is stored in the China Center of Industrial Culture Collection (CICC) and has a preservation number of 2238, as the enzyme-producing strain and uses wheat bran as the raw material; the solid fermentation technology is adopted for preparation; the fermentation and enzyme-producing capability is not less than 47000u / g (dry yeast), the liquid enzyme yield is not less than 85% and the soid enzyme yield is not less than 80%, which all achieve the food grade sanitation standard. The invention provides the acidic proteinase and the preparation method thereof, wherein the utilization rate of the fermentation equipment is high, the byproduct of crop processing is used as the main raw material, the enzyme activity for fermentation is high, the extracting and purifying rate of enzyme is high and the production cost is low. The acidic proteinase of the invention is suitable to be used as the raw material or product additive of the products in the leather industry, the pharmaceutical industry, the brewing industry and the feed industry.

The invention relates to a culture method of early-breeding seedlings of Charybdis japonica, which is characterized by comprising the steps of parent crab culture, egg-carrying crab culture, larva culture and the like. Aiming at the biological characteristics of the breeding of the Charybdis japonica, by utilizing the existing facilities for industrial culture of the seedlings of river crabs and the technical means such as regulation and control of ecological conditions, reasonable feeding, disease control and the like, the invention cultures the early-breeding seedlings of the Charybdis japonica required for culture production, the early-breeding seedlings have longer growth period and large scale in the market, and the economic benefit can be obviously improved. The experiment proves that the invention can realize industrial culture of the early-breeding seedlings of the Charybdis japonica, can solve the problem that seawater ponds in coastal areas are used for culturing the Charybdis japonica depending on natural seedlings, can fully utilize the existing facilities for the culture of the seedlings of shrimps and crabs and seawater culture ponds, improves the economic benefit of seawater culture in the coastal areas, has important economic significance and social significance, and has the characteristics of science, rationality, low investment and high practicability.

The invention aims to disclose a vitamin K2 high-yielding strain. Compared with the prior art, bacillus natto BS-5 is taken as an original strain, after the ultraviolet and nitroso arc composite mutation, the mutant strain BS-53 is obtained after screening, the mutant strain BS-53 and bacillus natto CICC (China center of industrial culture collection)10262 which has low vitamin K2 yield but high growth rate, are subjected to protoplast fusion, fusant is obtained through the screening of a flat screen, and the fusant is finally obtained after the selecting of the fermenting property experiment; and the vitamin K2 high-yielding strain has excellent characteristics of parents, i.e. has the dual effects of high MK (midkine) yield and high growth rate, an effective method is provided for realizing high MK yield, important scientific meaning and application value are obtained, and the purpose of the invention is realized.

The invention discloses a method for preparing a clostridium butyricum feed additive and a clostridium butyricum feed additive prepared by the method. The method for preparing the clostridium butyricum feed additive is characterized by adopting clostridium butyricum (the clostridium butyricum is preserved in the China Center of Industrial Culture Collection and the serial number is CICC 20036). The method comprises the following steps: such materials as tryptone, beef extract, yeast cream, glucose, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, magnesium sulphate, calcium chloride, ferrous sulfate, cysteine hydrochloride and the like are prepared into a dedicated liquid culture medium for seeds; strains are grafted into the culture medium for activating seeds; nitrogen source, carbon source and the like are prepared into a solid anerobic fermentation culture medium; and the seed liquid is grafted into the solid anerobic fermentation culture medium for solid state fermentation and then is dried and sieved. By utilizing the cheap nitrogen and carbon sources to form the medium, the invention provides a novel method for large-scale and industrial production of clostridium butyricum; and the method reduces the cost effectively and increases the benefits of plants.

The invention relates to an industrial fishpond water surface sewage cleaning machine which comprises a fixed rod, a movable rod, foam plates, magnets, suction heads, a self-sucking pump and sewage-sucking pipes, wherein one ends of the fixed rod and the movable rod are connected to the fixed foam plate, and the other ends are respectively connected with the two movable foam plates; the small magnets are respectively laid in the two movable foam plates; drop stones are arranged below the foam plates; the suction heads are arranged above the fixed rod and the movable rod and connected with the sewage-sucking rigid pipe; the self-sucking pump is arranged on a flat car outside a pond and connected with the sewage-sucking flexible pipe and a sewage discharge pipe, the sewage-sucking flexible pipe is connected to the sewage-sucking rigid pipe and connected outside the pond after penetrating through the sewage discharge pipe from the suction heads. The cleaning machine can effectively eliminate the sewage at the water surface of the industrial fishpond, has low cost, simple and convenient operation and removal efficiency of more than 93 percent, achieves the aims of controlling and improving the water quality of the culture pond, is an industrial fish culture special device and is suitable for industrial culture production at a large scale.

The invention discloses a pleurotus eryngii culture medium and an industrial culture method. The pleurotus eryngii culture medium comprises 20-40% of corn cob, 20-40% of bagasse, 5-15% of bran coat, 5-15% of corn flour and 10-30% of wood dust. The pleurotus eryngii culture method comprises the following steps: proportioning, bagging, sterilizing, discharging, cooling, inoculating, growing the bacterium, afterripening, scratching the bacterium, growing sporophores, collecting and the like. Compared with the prior art, the method has the advantage of abundant and accessible raw materials and greatly lowers the cost of the culture medium. Compared with the traditional formula, the culture medium disclosed by the invention has the following advantages: the hypha bagfull time is shortened by 1-4 days, the growth cycle is shortened by 3-6 days, and the yield per unit volume is enhanced by more than 60% as compared with the conventional one-stubble culture.

The invention relates to a blowdown device in a prawn breeding system, in particular to a gas lifting type decontamination device suitable for prawn indoor industrial culture.The gas lifting type decontamination device suitable for prawn indoor industrial culture comprises a guiding pipe, a top tray, a blowdown sleeve, an aeration pipe and a base plate, wherein the base plate is arranged at the lower end of the guiding pipe and installed on a blowdown port of the prawn breeding system, the guiding pipe is sleeved with the blowdown sleeve which can slide up and down along the guiding pipe, water drainage holes are formed in the position close to the lower end of the blowdown sleeve, the aeration pipe is arranged at the lower end of the blowdown sleeve in the peripheral direction, and the top tray is arranged on the top of the blowdown sleeve and further provided with an inflating port.Bubbles overflow to disturb living prawns so that the prawns can leave the blowdown port and cannot be affected by sewage, and meanwhile, by lifting the blowdown port through gas, dead prawns, residual feed and faeces in a prawn pond are fast removed.

The invention discloses a compound feed of parabramis pekinensis. The feed is mainly prepared from the following raw materials in parts by weight: 10-20 parts of duckweed powder, 10-20 parts of bean pulp, 2-7 parts of chicken intestine powder, 2-6 parts of shell powder, 1-8 parts of earthworm powder, 5-10 parts of corn stalk powder and 3-8 parts of wheat stalk powder. The compound feed disclosed by the invention material has the beneficial effect that the duckweed powder which is rich in nutrition, wide in source and low in price in the materials is used as the primary raw material; the duckweeds are favorite floating algae of the parabramis pekinensis, and are matched with the bean pulp, the chicken intestine powder, the shell powder, the earthworm powder, the corn stalk powder and the wheat stalk powder so as to be eaten, so that the appetite of the parabramis pekinensis is effectively promoted, and the growth efficiency of the parabramis pekinensis is improved; besides, the compound feed is rich in feeding nutrition, low in price, simple to prepare and beneficial to large-scale industrial culture.