Analysis of the Problems in Greenhouse Construction?

In recent years, the construction of farming greenhouses has gradually increased. However, when building greenhouses in some areas, they often ignore the local natural conditions, resulting in many problems, not only shortening the life and practicality of the greenhouses, but also reducing the yield and quality of vegetables, resulting in unintended Economic losses. Therefore, the farming greenhouse installation company takes the issues that are prone to occur in the construction of greenhouses, to remind vegetable farmers everywhere to avoid such problems.

1. Too little space between the two greenhouses will affect the light. Vegetables suffer from "cold disorders" due to low temperatures. At the same time, due to lack of light, the growth of vegetables could not perform photosynthesis normally, which led to "fat and yellow muscles" and even "hunger" and died.

2. Lack of drainage system. In the season with heavy rainfall, it is easy to cause the greenhouse to collapse or cause the roots and dead trees of vegetables and other plants to grow, resulting in huge economic losses.

3. No protective measures are taken on the back wall of the greenhouse, which can easily shorten the useful life of the greenhouse.

4. The pillars in the last two rows of the greenhouse are too far away and the pressure is too small. To build a greenhouse, steel pipes are used as the skeleton. The taller pillars in the greenhouse are 5.8 meters (60 cm below the ground). Wall height of about 4.5 meters.

Farming Greenhouses

5. Digging deep inside the greenhouse is not conducive to the growth of vegetables. It is more appropriate to dig 0.5-1. 2 meters in the greenhouse. During the construction of the greenhouse, it must be emphasized that the soil for the wall must also be excavated from the ground in front of the greenhouse, and the depth of the excavation depends on the situation, which is generally more than 0.5 meters. Building a greenhouse in this way can make the front face of the greenhouse only have a depth of less than 0.6 meters, reduce the area of the shading belt, and improve the insulation performance of the greenhouse.

6. When the greenhouse is used to build the wall of the mature soil in the greenhouse, the exposed surface is a layer of raw soil with low organic matter content, lack of beneficial microorganisms and poor air permeability. If it is not modified, the growth of vegetables in the season will be affected , Resulting in huge economic losses.

7. In building greenhouses, we must always adhere to the "measures according to local conditions" approach. For example, in some areas with shallow tillage levels and low groundwater levels, it is necessary to avoid the construction of "semi-underground" greenhouses, and no "cellar" greenhouses should appear. The depth of excavation should be minimized or a greenhouse should be built directly on the ground.

The Structure of the Glass Greenhouse

Glass greenhouse structure mainly includes greenhouse foundation, greenhouse steel structure and aluminum alloy structure.

1. Foundation classification: commercial glass greenhouse foundation is divided into two types of independent column foundation and strip foundation. Independent foundations can be used for inner or side pillars, and strip foundations are mainly used for side walls and inner partition walls.

2. Design requirements: Before the foundation is designed, the geological data of the construction site should be carefully analyzed. First, the site geological survey report (for important large-scale greenhouse projects); second, construction site testing (for general projects) The third is based on experience and reference geological data of nearby projects (for small projects). In foundation design, in addition to meeting the strength requirements, it should also have sufficient stability and ability to resist uneven settlement. The foundation connected to the support between columns should also have sufficient horizontal force transmission and spatial stability.

The bottom of the greenhouse should be located below the frozen soil layer. The heating greenhouse can consider the impact of heating on the freezing depth of the foundation according to the climate and soil conditions. Generally, the bottom of the foundation should be more than 0.5 meters below the outdoor ground, and the distance between the top of the foundation and the outdoor ground should be greater than 0.1 meters to prevent the foundation from being exposed and adversely affecting cultivation. Except for special requirements, the distance between the top surface of the greenhouse foundation and the indoor floor should be greater than 0.4 meters. The embedded parts connected to the steel structure of the greenhouse are set on the top of the foundation. The design of the embedded parts is also an important part of the foundation design. The connection methods of the embedded parts and the superstructure mainly include hinge, consolidation and elastic connection.Depending on the connection method, the design and construction methods are different, but all embedded parts must ensure a good connection with the foundation and ensure that the superstructure is transferred. The incoming force is correctly transmitted to the foundation.

3. Basic materials and construction characteristics

(1) Independent foundation. Reinforced concrete is usually used. In terms of construction methods, the independent foundation can be divided into two methods: full cast and partial cast. All-in-situ pouring is carried out by using the construction site supporting mold and integral pouring method; part of the in-situ pouring method is carried out by using the method of prefabricated short columns and on-site pouring of the foundation cushion. Two methods can be chosen according to the specific situation. The cast-in-place method has the characteristics of good integrity and low cost; some cast-in-place methods have higher cost but faster construction speed and easier construction quality.

(2) Strip foundation. Masonry structures (bricks and stones) are usually used, and construction is also carried out on site. A reinforced concrete ring beam is often installed on the top of the foundation to install embedded parts and increase the stiffness of the foundation. In addition, the side wall foundation can also use a combination of independent foundations and strip foundations.The bottom of the two types of foundations can be located at the same elevation, or they can be set at different elevations according to the bearing capacity and function; the independent foundation undertakes the bottom of the greenhouse In the case of forces, the strip foundation is only used as part of the separating element. (3) Precautions for foundation construction. During the construction of the foundation, the column height and the axis position must be ensured to be correct. Equipment, pipeline openings and installations must be buried in time. It is forbidden to dig after construction to damage the foundation.

 Planting Greenhouse

Steel structure

1. Steel structure content: It mainly includes support, connection parts, and solid parts for the bearing structure of the planting greenhouse and the structural stability. 2. Materials and Precautions for Construction Steel materials are mainly cold-formed thin-walled steel and hot-rolled steel. Except for a few components, high-strength steel is used, and the rest of the steel is A3F. Glass greenhouse steel framework is generally produced by specialized factories. Because the greenhouse components are in the indoor high humidity environment for a long time, all structural components should be treated with anticorrosion. It is usually treated by hot-dip galvanizing. In order to ensure the effect of anticorrosive treatment, all components should be anticorrosive after processing. It is not allowed to cut, saw, and weld the greenhouse components on the spot. If there is a small amount of on-site operations, it is also necessary to perform anti-corrosion treatment, spray anti-corrosion paint on the processing or wound. The installation of the skeleton should be carried out in strict accordance with the drawings and relevant standards, specifications and regulations.

3. Design considerations: vegetables greenhouse manufacturers must consider structural strength, structural rigidity, structural integrity, and structural durability in their design.

2. Aluminum alloy

1. Function: Aluminum alloy is used as the main inlay and cover support member of glass greenhouse. Its main functions are: (1) cooperate with rubber seals as a part of the glass greenhouse cover sealing system; (2) use alone, as a greenhouse roof support Components and sealing components; (3) used as a gutter.

2. Design requirements: The main part mainly meets the requirements of strength and rigidity; the support part as the support of the glass is mainly reserved for some long-length support grooves or inlaid grooves; the inlaid part located outside the glass must be provided with special rubber Sealed grooves can be used to fix rubber seals, and can also be used with small aluminum or stainless steel parts to fix glass.

Four Points to Note When Building a Greenhouse

Farmer friends need to pay attention to the following four points when constructing greenhouses:

(I) Lack of drainage system in rainy season

Many farmers did not consider the problem of drainage in the shed when they built the shed, and there was no precautionary measure, so that during the heavy rain in summer, the rainwater left on the shed surface was collected at the "front face" of the shed, and there was no local flow. Not leaving, even the phenomenon of the front of the greenhouse being washed out. The correct method is to dig a drainage ditch from the front of the shed to the same length as the greenhouse. The drainage ditch is about half a meter wide and about 30 centimeters deep. So that the water left on the greenhouse surface can flow away at any time to prevent water from flowing into the greenhouse.

(2) The distance between the two columns in the back row is too large

Between the last two rows of columns in the greenhouse, the roof part of the roof is often the part where the rolled straw curtain and roller shutter machine are parked. This part can be said to be under the pressure, which often makes the Skeleton deformation. The distance between the two rows of columns should be as small as possible, and it should be about 80 centimeters. Only one cement trench and sidewalk running in the middle can be built in the middle.

(3) Too little space between the two sheds

In order to save land for some farmers, the distance between the two sheds is too narrow, and some are only about 2 meters, leaving hidden dangers in the greenhouse. In winter, the front greenhouse is too shaded to the back, which makes the first half of the greenhouse unfavorable for vegetable growth. Secondly, the harm to drainage is greater. When it snows in winter, it may not be piled up in front of the snow removal shed. Therefore, the correct distance of the open space between the two sheds is preferably 4-5 meters, so that they can not shade each other, but can also be windproof.

(4) Lack of protection measures for the backslope

Some farmer friends have no covering facilities at this part of the back slope, so that they are often washed away by rain in summer, which affects the useful life of the greenhouse. Although some shacks are covered with a layer of plastic cloth on the back slope, they are often exposed to the wind and sun, and the back slope is exposed again within a year. Therefore, a layer of plastic cloth should be wrapped on the back slope of the greenhouse, and then a layer of non-woven cloth should be coated on the outer bread. Use a steel wire every 10 meters or so to ensure that there will be no major problems for about five years.

Agricultural Greenhouse Plastic Film

Matters needing attention when changing the film in the greenhouse construction:

1. Bamboo poles in greenhouses must withstand the weight of grasshoppers. When the snow is heavy, the bearing capacity will increase greatly, which will cause some bamboos to be crushed or broken. Such bamboo poles must be maintained or replaced in time. For the bamboo rod that has been crushed, you can remove it and replace it, or attach another one beside the broken bamboo rod. The original broken part is wrapped with a cloth strip to prevent puncturing the shed film. The bamboo poles that can be used only after the crack appears, can be wrapped with a cloth strip.

2. Vegetable greenhouse construction The bottom of the steel wire on the gable wall is used to pad used car tires or soles, etc., to increase the area under which the steel wire is stressed, and to prevent the steel wire from getting into the gable.

3. The glass greenhouse for vegetables is constructed with rags, rubber pipes, PVC pipes, etc. on the shed surface and the front corner, or plastic hoses are placed on the laminated rope to avoid the laminated rope and the shed. The film is in direct contact, which reduces the friction between the pressing rope and the shed film, and slows down the wear rate of the shed film.

4. The construction of vegetable greenhouses should shorten the time from the removal of the old film to the replacement of the new film. At present, vegetable farmers are multiple partners to help each other change the film. The bamboo rods to be replaced can be prepared in advance. The new film can be raked in front of the shed, and then the old film can be removed. Overlay, thus shortening the film changing time.

5. Poor quality membranes and old membranes in vegetable greenhouses are not good in defogging and dripping in winter, and dew is easy to produce when air is released, which results in high air humidity in the greenhouses, which is not conducive to disease prevention. It is recommended that the agricultural greenhouse plastic film be replaced once a year, and replaced with a film of better quality and strong anti-fogging and dripping properties.

The Quality of Greenhouses Is The Core of Market Competition!

Features of insulating glass in greenhouses: The periphery of the greenhouse is made of insulating glass. It is an excellent product. It plays the same role as the skin in the greenhouse system. Generally speaking, the insulating glass of the greenhouse is composed of two or more pieces, and the periphery is sealed.

With the advancement of skills, greenhouse gas emission rights are normal, and the results of vacuum glass thermal insulation, sound insulation and noise reduction are getting better and better, and the glass's own mass has decreased, but the load capacity has increased. Insulating glass, with its excellent features of dew condensation prevention, energy-saving insulation, sound insulation and noise reduction, China's greenhouse project has taken it to the next level, walking in front of the world's greenhouses. So what are the characteristics of insulating glass in greenhouses? How to correctly understand the importance of the greenhouse skeleton! vegetables greenhouse manufacturer share with you:

First, the selection of insulating glass is very good. The use of flexible sealing material as the material can reduce the shear force in the sealing area of the glass plate in the case of large temperature difference between the surface and the room, and overcome the failure of the brittle sealing material in the same environment. In this way, the loopholes of the greenhouse's own loss of achievements in many types of severe conditions have been eliminated.

Agricultural Glass Greenhouse

Second, the hollow glass has a high vacuum inner cavity. This is the feature that distinguishes it from other glasses. Negative gas heat transfer almost does not exist. It greatly prohibits the heat transfer of radioactive materials and ensures the heat transfer of glass. The insulation and insulation of the insulating glass in the greenhouse is twice as high as that of ordinary glass, which can satisfy the requirements for heat transfer and cooling of doors and windows.

Third, agricultural glass greenhouse selects low temperature sealing skills. On the one hand, it has the characteristics of toughened glass and resistance to attack. On the one hand, its force is well-balanced, and it will not cause damage due to collision and other reasons. It will increase the service life and is the first choice for building greenhouses. Although the insulating glass of the greenhouse can also cut off the noise and ensure the normal production of employees, in order to ensure the energy saving benefits, greening and environmental protection, choosing the growth mode of the greenhouse is the main choice for building greenhouses.

What are the factors affecting greenhouse durability?

The durability of the greenhouse is affected by the aging resistance of the greenhouse material and the bearing capacity of the main structure of the greenhouse. Multi-span greenhouse is a kind of better existence of greenhouse, in fact, it is a kind of large greenhouse. It connects the original single-room greenhouse with scientific methods, reasonable design and excellent materials to connect the original single-room greenhouse. Compared with traditional greenhouses, greenhouses and greenhouses in the form of multi-story greenhouses are a bright spot compared to traditional greenhouses, and their utilization area is much larger than traditional greenhouses. Compared with traditional greenhouses, the management is more unified, the operation is more scientific, saves time, and increases efficiency. In addition to the strength of the transparent material, in addition to its strength, it also shows that the light transmittance of the material decreases due to time, and the degree of attenuation of the light transmittance is a decisive factor affecting the service life of the transparent material. Due to the long-term operation of the greenhouse in high-temperature and high-humidity environments, the surface corrosion of components has become one of the important factors affecting the service life of the greenhouse. In greenhouse steel structures, thin-walled steel is generally used as the main stress member, and its corrosion resistance is poor. Greenhouse anticorrosive treatment uses hot-dip galvanized surface. For greenhouses with wooden or steel welded truss structures, surface anti-corrosion treatment is guaranteed once a year.

The waste heat in the equipment is discharged to keep the indoor ambient temperature within a range suitable for plant growth. The discharge of residual humidity is to keep the relative humidity of the indoor environment within a range suitable for plant growth. Adjust the air composition, reduce harmful gases, increase the CO2 content in the indoor air, and make the crop grow well.

Due to the long-term operation of the greenhouse in high-temperature and high-humidity environments, surface corrosion of components has become one of the important factors affecting the service life of the greenhouse. With the development of vegetable greenhouses in recent years, greenhouses have provided a driving force for agricultural development. Greenhouse control generally consists of three parts: signal acquisition system, computer and control system. In greenhouse steel structures, thin-walled steel is generally used as the main stress member, and its corrosion resistance is poor. Greenhouse anti-corrosion treatment should use hot-dip galvanized surface. The coating thickness reaches 150-200 microns, which can guarantee a 15-year service life. For greenhouses with wooden or steel welded truss structures, the surface of the greenhouse is protected from corrosion once a year.

Development Prospects of Greenhouse Ventilation

The popularity of automatic ventilation pillarless environmental protection greenhouses is the primary development trend of greenhouse ventilation development. This greenhouse is composed of plastic lighting film, wall, main frame, lighting device, and thermal insulation equipment. The wall frame and polyethylene film frame together form the main frame of the greenhouse, supplemented by wall insulation board and polyethylene. The film frame and the setting of automatic ventilation windows at the upper and lower slopes are important characteristics of the environmentally friendly greenhouse without pillars. The environmentally friendly greenhouse without pillars is not affected by the temperature and the surrounding environment of the greenhouse. , Fruits, vegetables, aquaculture, land farming, rice seedlings and other fields. Because this kind of greenhouse sheds all the pillars that affect ventilation, it reduces the cost of the greenhouse and reduces the labor intensity; the surface of the greenhouse is smooth, which enhances the strength of air circulation, and is very straightforward to realize automatic ventilation in the greenhouse.

Standardized greenhouses have become the mainstream of greenhouse ventilation:

The standardized greenhouse greenhouse becoming the mainstream of greenhouse ventilation is the second development trend of greenhouse greenhouse ventilation development. The regulation of the air humidity in the greenhouse and the regulation of the air composition in the greenhouse must be solved by the greenhouse ventilation. Therefore, the development of the greenhouse ventilation needs a series of ventilation regulations to control, such as: to what extent the air humidity in the greenhouse must reach Ventilation control etc. need to be standardized. The span of the greenhouse should be conducive to the circulation of air in the greenhouse. If the span of the greenhouse is too large, the arch of the greenhouse will be relatively small, and the rate of air replacement will be accelerated, so that the temperature in the greenhouse cannot meet the needs of crop growth in a long time , Affecting the growth of crops in the shed. The design of the steel frame must also meet the requirements for the ventilation of the greenhouse. The density of the columns, the diameter of the breast diameter and the design of the steel mesh on the roof must not only meet the requirements of compression resistance, but also fully consider the requirements of ventilation. Generally, the steel mesh should be kept At a distance of about 15 cm, it is evenly spread under the ventilation film in the greenhouse.

China Glass Greenhouse For Vegetables

Realize the intelligent control of china glass greenhouse for vegetables:

Realizing intelligent control of greenhouse greenhouse ventilation is the third development trend of greenhouse greenhouse ventilation development. The development of greenhouse ventilation has gone through the phases of manual control ventilation and automatic control ventilation, and it is bound to develop to intelligent control of greenhouse ventilation. In the early stage of the development of greenhouses, greenhouse ventilation was generally completed manually. The employees of the greenhouses were both the managers of the greenhouses and the feelers and performers of the greenhouse ventilation. When they felt that ventilation was needed in the greenhouses, they opened the roof or The cracks on the side of the shed provide ventilation. When to ventilate and the maintenance of ventilation practices are judged based on the long-term accumulation of experience and feelings of the greenhouse practitioners, which directly results in a low ventilation effect. With the development of science and technology, the automation control technology has been greatly developed. The automation control technology has gradually been applied to the ventilation of greenhouses. Through the establishment of computers and automatic control systems, the greenhouse ventilation has realized automatic regulation and automatic ventilation. Various sensors in the greenhouse can automatically collect technical parameters such as air temperature and humidity, carbon dioxide content in the greenhouse, and the automatic control system compares the actual measured data with the preset values to determine whether to perform ventilation. The realization of greenhouse ventilation rack has further improved labor productivity. Based on production practice and automation of greenhouse ventilation, intelligent greenhouse ventilation is collected. By collecting various data in the greenhouse, summarizing, experimenting and analyzing, constructing various expert systems to follow the growth of crops in the greenhouse Model, develop the expert ventilation control system suitable for different crops in the shed. Through this system, the real-time data is processed in time, the ventilation scheme is automatically analyzed and selected, the ventilation operation is performed, and the intelligent control of the ventilation in the shed is realized.