Current situation and development direction of con

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Current situation and development direction of concrete mixing plants in China

current situation and development direction of concrete mixing plants in China

information on China's construction machinery

Guide: due to the continuous advancement of China's urbanization process, ready mixed concrete has been rapidly developed, popularized and applied in large and medium-sized cities across the country, and concrete mixing plants have also developed at a high speed. At present, there are many concrete mixing plant production enterprises in China, and the products have formed a series, but the technical level is uneven, only some

due to the continuous progress of urbanization in China, ready mixed concrete has been rapidly developed and popularized in large and medium-sized cities across the country, and concrete mixing plants have also developed at a high speed. At present, there are many concrete mixing plant production enterprises in China, and the products have been serialized, but the technical level is uneven. Only some products are close to the international advanced level, and some technologies have exceeded the level of imported concrete mixing plants. Some products have automatic use of vision, smell, touch, high production capacity, high weighing accuracy, low investment, good mixing quality, and can realize multiple warehouse numbers, multiple mix proportions Continuous production and the high degree of localization of the main machine and its main components have the advantages, but China's concrete mixing plants still have the disadvantages of low overall technical content, low popularity, large regional differences, low degree of intelligence and low environmental protection performance

advantages of concrete mixing plants in China 1 The concrete mixing plant with high reliability has been developed in China for more than ten years. Its development process is to introduce - Digest - some domestic - all domestic - improve and improve. It is normal for ordinary concrete companies to continuously produce 10000 cubic meters of concrete, and the performance of its key components such as host machine, screw machine, main control and pneumatic components has been quite stable. For example, the mixing blade adopts a unique high chromium and high manganese alloy wear-resistant material, and the shaft end support and sealing form adopts a unique multiple seal or air tightness, which greatly improves the reliability of the host machine. Wear resistant steel plates are used to strengthen the parts that are often impacted and easy to wear, such as discharge hoppers, transition hoppers, etc; The ring belt joint is vulcanized and bonded, and its service life is 3 times longer than that of ordinary steel riveting, which is a prerequisite to ensure its high reliability

the degree of automation is high. After 2002, many concrete companies began to adopt the mode of two main machines in parallel, which solved the problem of ensuring one standby and reducing the waiting time of concrete trucks while improving production capacity. At present, most of its control systems are relatively advanced and stable, and the degree of automation is generally high, which can be fully automatic and continuous production for a long time. The operation platform and computer monitoring in the control room can vividly reflect the whole production process and the situation of each part, such as the cement storage in the cement silo, the aggregate storage in the aggregate silo, the aggregate transportation and concrete discharge. Once a problem occurs in a certain part, it can be found in the shortest time and solved in time

all mixing stations are controlled by industrial computer, which can be controlled automatically or manually, and the operation is simple and convenient. Dynamic ◆ 2 The purpose and significance of the development of bio based high molecular materials panel displays the operation of all components of the mixing plant, and can store all kinds of data of the mixing plant, print all kinds of report materials as required, and store more than tens of thousands of formulas. The control room is equipped with air conditioning to ensure the durability of electrical components, stable and reliable performance. The control system basically adopts two ways, one is in the form of dual computer and dual control, that is, the system is composed of two high-performance industrial computers, one as the main control production system, the other as the management and monitoring system and also as the backup machine of the main control production machine. As the main control system, it has manual and automatic functions, The data is shared between the control machine and the management machine. When the control machine fails, it can be switched to the management machine to work, so as to ensure the continuous normal operation of the system to the greatest extent. The other is composed of industrial computer and batching control instrument, that is, the data of batching control instrument is input into industrial computer, and the execution signal is output through board card or PLC programmable controller, so as to ensure the continuous and normal operation of the system. Surveillance cameras can be set at the discharge port of the host machine, batching station and other key components

high production capacity. At present, the emergence of double parallel stations and multiple parallel stations has greatly improved the production capacity of major concrete companies. For example, two 120 parallel stations can increase the annual output of concrete to 600000 cubic meters, and three parallel stations can increase to about 800000 cubic meters, fundamentally solving the problem of insufficient production capacity that restricts the further development of most companies

high measurement accuracy the measurement accuracy of concrete mixing plant is divided into four aspects, namely, aggregate, cement, water and additives. The accuracy of aggregate is generally controlled within ± 2%, the accuracy of cement is generally controlled within ± 1%, the accuracy of water is generally controlled within ± 1%, and the accuracy of additives is generally controlled within ± 1%. The aggregate is generally measured by belt weigher and weighing bucket. The belt is called cumulative weighing, and the weighing bucket is used for separate weighing or cumulative weighing. The weighing of cement and powder is generally carried out by weighing bucket. When there are many kinds of powder, cumulative weighing or separate weighing is adopted. Generally, there are two ways of water measurement: volumetric and weighing. Volumetric is divided into time measurement, quantitative water meter measurement and turbine flowmeter measurement; Weighing type is divided into self falling drainage weighing device, pressurized water pump drainage weighing device and integral weighing barrel structure; The weighing of admixtures includes volumetric, mass and pulse meters

imported components are used for weighing, control and signal conversion of aggregates, powders and water agents. High precision sensors, imported microcomputer control, and individual or cumulative weighing of each scale fully ensure the accuracy of measurement and stable working performance

it is not only beneficial to the transformation and upgrading investment of enterprises, but also the investment of provincial Concrete Companies in mixing plants is less than that of other pumping equipment. For example, if one 120 station is well configured, it will not exceed 2million yuan, and two 120 parallel stations can also be controlled at about 3.6 million yuan

good mixing quality. When the mixing machine is working, the transmission mechanism drives the two mixing shafts to rotate synchronously and reversely. Four to eight mixing arms and two opposite mixing arms are arranged on each mixing shaft, which are equipped with mixing blades and scrapers. After the materials are put into the mixer, the coarse and fine aggregates and admixtures are stirred by the mixing blades and scrapers to make the mixture move radially and axially in the middle of the tank, Convection is formed in the cross area between the two mixing shafts to realize strong mixing of materials, so as to make the mixing quality better and more uniform

the double horizontal shaft forced mixer has strong mixing capacity, uniform mixing quality and high productivity. For the mixing effect of dry hard, semi dry hard, plastic and various proportions of concrete, it is good to add 4% carbon nanotubes (surface modified with PVDF) into PMMA by solution blending ultrasonic dispersion method. The lubrication system and the spindle drive system are all imported with original packaging, and the hydraulic door opening mechanism can adjust the opening of the discharge door as required. The mixing shaft of the mixing machine adopts anti adhesion technology to effectively prevent the cement from caking on the shaft. The shaft end seal adopts a unique multiple sealing structure to effectively prevent mortar leakage and ensure the continuous and long-term operation of the whole mixing system. The cleaning system adopts automatic control and manual control of high-pressure water pump, and each water outlet is located directly above the mixing spindle to improve the mixing efficiency, increase water mist, reduce dust pollution, and effectively remove cement caking

the degree of localization of the host and its main components is high. In recent years, many mixing plant manufacturers in China have successively developed host machines of many brands by absorbing foreign host technology, such as Siemens host machine with Italian technology, skoma host machine, host machine with German BHS technology, etc., which to a certain extent solves the situation that the quality defects that have plagued the mixing host machine for many years in China have not been solved. At present, most of the main components and parts are electrical and hydraulic components made by Sino foreign joint ventures or wholly foreign-owned enterprises, such as Toledo, Schneider, Siemens and Omron, which are relatively stable, so that the cost of domestic stations has been greatly reduced, and the quality and stability are no less than that of imported mixing stations

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