The buckwheat belongs to the seed plants, angiosperms, and dicotyledons. It is considered to be the most important food resource in the 21st century because of its high nutritional value, coolness, anti-inflammation, helping digestion, and delaying aging. Xuanwei buckwheat cultivation has a long history of cultivation. It can be planted throughout the city. The varieties are mainly buckwheat buckwheat and sweet buckwheat. They can be planted in spring, summer and autumn, mainly in autumn quinoa to make buckwheat productive. To stabilize production, you must understand the following.
First, the morphological characteristics of buckwheat 1. Root: straight root, consisting of the main root, lateral roots and root hair. The main root is buried in 30-50cm, and the suction fertility is strong, especially the absorption of phosphorus and potassium, so it is suitable for cultivation in the new depression and barren land.
2. Stems: The stems of most buckwheat are upright, with smooth or glabrous surfaces, round and juicy, slightly angular, solid when young, and hollow when mature. Stem green, purple or red.
3. Leaves: Leaves consist of leaves and petioles. The leaves are round and sinuous, the base is dimpled, and the palmate veins. The bitter green leaves are small and green. Sweet medlar leaves are large, brownish red, and the leaves are smooth and glabrous, usually green.
4. Flowers: Infinite inflorescences, general. Small bitter buckwheat, no nectaries, no scent, white or light green, flowers are sparsely sparse, self-flowering, all flowers can be pollinated, sweet pods are large, scented, dense flowers, are all cross-pollination crops The nectaries at the base are well developed and attract insects to pollinate.
5, fruit: Most of the three-angle type, there are few irregular or polyhedral irregular type. Shapes are triangular, long oval and so on.
Second, buckwheat requirements for growth conditions 1, light: buckwheat is a short-day crop. Sweet buckwheat is sensitive to sunshine; buckwheat does not require strict sunshine, and can grow and form fruit under long-day and short-day conditions. The same variety of spring sowing bloom late, long growth period; summer sowing, early flowering, short growth period.
2, temperature: buckwheat is a warm crop, chills, cold capacity is weak, suitable for growth and development of the temperature range of 14-30 degrees. The spring temperature for sweet hoarding was 1581 degrees in spring, 1651 in summer, and 1717 in autumn, and 1841 in taro.
3. Moisture: Buckwheat is warm and humid, the seeds germinate to emergence, the water requirement is 40-50% of the seed weight, and the water requirement of the plants after budding increases sharply, but pollination is strong under the climatic conditions of foggy and rainy weather. It will also be affected.
4. Soil: The requirements of quinoa for nutrients are generally to absorb more phosphorus and potassium, and the application of phosphorus and potassium fertilizer has a significant effect on increasing the yield of buckwheat, resulting in excessive nitrogen fertilizer, strong growth and top-heavy, and easy lodging. Strict requirements for soil, Any soil can be grown.
Third, the technical points 1, fine soil preparation, improve the quality of sowing: the required depth of about 20 cm tillage, to avoid the shallow plough or no-tillage, the plough flattened to clear the former crop residue and weeds, so that loose topsoil, is conducive to sowing And emergence, and pay attention to trench drainage.
2. Rational fertilization: (1) Apply enough base fertilizer and increase phosphorus and potassium fertilizers. Mu Shi fermented farmyard fertilizer 500-1000 kg, in the soil preparation together into the soil, sowing urea 3-5 kg, 15-20 kg of phosphate fertilizer, potassium fertilizer 3-4 kg and fine farmyard fertilizer 50 kg mixed seed dressing. (2), skillfully applying topdressing, that is, before the flowers to see seedlings Mu recovery 3-5 kg.
3, timely sowing: Requirements in the case of competing with other crops, sowing as early as possible, to avoid frost damage in the late, high cold and cool areas should be planted before the beginning of autumn, other regions by no later than August 20th. The per mu sowing volume is 5-8 kg. Drilling is used to evenly distribute the seeds in the ditch, and the line width is maintained at about 20 cm.
4. Strengthen field management and prevent pests and weeds in a timely manner: (1) Weeding: When the seedlings grow to 6-8 cm in length, artificial weeding is performed for the first time, the second time is performed before flowering, and soil is combined with earth. It can prevent buckwheat from overturning and promote high yield. (2) Insect repellent: Insect repellent is mainly used in flowering period, supplemented by insect repellent at seedling stage. Use kung fu, enemy killing and other pesticides to prevent and control. (3) Pollination: Insects and wind pollination are the main factors in flowering, combined with artificially-assisted pollination to increase the seed setting rate.
5, timely harvest: generally require 70% of the whole plant grain can be harvested when mature. Promote early harvest, light harvesting at harvest, local threshing or moving to the drying yard for threshing.
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Double-Wall Plate Heat ExchangerGasketed plate heat exchangers (PHE) meets almost all of heat transfer requirements. They are highly flexible with a wide range of models. Connection sizes range from 1″ to 16″. Plate materials are available in a wide variety such as stainless steel 316, 304 and titanium. Other alloys for corrosive applications such as Hastelloy, Nickel and monel are also available.
A flat Plate Heat Exchanger transfers heat between two different fluids using metal plates to separate the fluids. The fluids move between the gaps in the plates. The plates are corrugated in a chevron pattern causing high turbulence in the fluids. The high turbulence and high surface area of the plates results in a higher efficiency of heat transfer than conventional shell and tube heat exchangers.
Advantages of Plate Heat Exchangers:
Because the flow pattern causes high turbulence of the fluids through alternate channels – this results in a higher heat transfer rate allowing for a more compact design reducing material cost since the heat transfer surface requirement is much lower than a conventional heat exchanger.
High turbulence results in less fouling – therefore less down time for maintenance.
Easily add capacity as expansion is required by adding plates to the heat exchanger.
Can be opened without disturbing the piping.
Closer temperature approaches of up to 2°F maximizes heat recovery for a wide variety of applications.
Minimal space required for opening or closing the heat exchanger allows for easy maintenance.
Ideal for mounting on a skid.
Flow principle of Plate And Frame Heat Exchangers:
Plate and frame heat exchangers consists of a pack of thin metal plates with openings for the passage of the fluids. The plates are corrugated which means that each pair of adjacent plates in the heat exchanger forms a channel. Every second channel is open to the same fluid. Between each pair of plates there is a rubber gasket, which prevents the fluids from mixing and from leaking to the surroundings.
When the media enters the plate and frame heat exchanger via the connections in the frame, it`s directed through alternate channels by the gasket arrangement. The warm fluid flows through every other channel and the cold fluid through the channels in between. Heat is thus transferred from the warm fluid to the colder fluid via the dividing wall, i.e. the plate material. The corrugations support the plates against differential pressure and create a turbulent flow in the channels. In turn, the turbulent flow provides high heat transfer efficiency, making the plate heat exchanger very compact compared with the traditional shell-and-tube heat exchanger.
The Double-Wall Plate Heat Exchanger:
For fluids that must be kept separate
The Double-Wall Plate Heat Exchanger is a technical breakthrough for heat exchange for media between which a hostile or undesirable reaction can occur, if the two fluids should mix. The Double-Wall Plate Heat Exchanger is therefore a new alternative to traditional heat transfer equipment such as the double-wall shell-and-tube heat exchanger, the triple-tube shell-and-tube heat exchanger, the double-circuit intercooler, and coils for indirect heating.
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