In the construction of asphalt pavement, asphalt mixing station plays a key role. The performance of asphalt mixing station and the working condition of asphalt mixing station directly affect the quality of asphalt mixture, which is related to the quality of the whole project and the progress of the whole project. Therefore, the current asphalt mixing station control technology is increasingly advanced and the content of science and technology is increasing, which requires mechanical operators to continuously improve their operation skills, to meet the construction needs, to ensure the normal operation of machinery, to give full play to its due efficacy, to ensure the quality of the project, to ensure the progress of the project. Then how can we ensure the normal operation of machinery and give full play to its due efficacy?
Firstly, the operator should master the structure and working principle of each part of the mixing station skillfully. On this basis, the production details, especially the metering system, should be strictly controlled, because the working condition of metering directly affects the technical index of asphalt mixture.
For stone metering system, attention should be paid to:
(1) Keep the unloading doors open and close flexibly and quickly;
(2) The unloading ports should be kept unblocked without sediment, so that the stone can flow down quickly and evenly when measuring.
(3) The unloading doors should be closed in time and sealed well. No leakage should occur at the end of single material measurement.
(4) around the aggregate weighing hopper, keep it clean, no foreign body is allowed, so as not to jam the hopper, and ensure that the aggregate weighing is in full suspension at all times.
(5) Each aggregate weighing sensor should have balanced preload, uniform force and sensitive induction.
For powder metering system, the following points should be paid attention to:
(1) Keep the powder conveying pipeline unblocked, and there should be no blocking phenomenon;
(2) Feeders or valves should be sealed tightly and practically, and powder should not be leaked at the end of measurement.
(3) Frequently remove dust and debris from powder measuring hopper to keep it clean;
(4) The whole metering system should be well sealed to prevent powder from moisture and caking.
(5) Powder material says that unloading should be thorough, that there should be no residual powder inside, that unloading door should be closed strictly, and that powder should not be leaked when measuring.
Attention should be paid to asphalt metering system:
(1) Before starting production, the pipeline should be heated sufficiently to ensure that the asphalt temperature in the system reaches the required value;
(2) The asphalt spraying pipeline should be clean and unblocked, and the nozzle should not be blocked, otherwise the spraying is not uniform and the mixing effect will be affected.
(3) The asphalt spraying pump or valve should be closed tightly to ensure that there is no leakage after the asphalt spraying.
(4) The operation of the asphalt metering conversion valve should be accurate, timely and well sealed. The suspension of the asphalt metering barrel should be firm and flexible.
For the whole metering system of asphalt mixing station, operators should check it regularly. Check whether the weighing gauges are completely in suspension state, whether there is jamming phenomenon, check whether the weighing sensors work properly, and whether the induction is sensitive. Regular check to make the display value consistent with the actual value. If problems are found, they should be solved in time to ensure that the metering system is in good working condition at all times.
Secondly, the operator should accumulate rich experience, be able to predict most of the mechanical failures, as soon as possible to solve and eliminate hidden dangers. After the failure occurs, it should be able to accurately judge and remove it in time to ensure the normal use of machinery. In order to do this, the operator should not only maintain the machine in time according to the rules, but also do the following:
(1) Operators should inspect frequently, observe carefully, and examine frequently moving parts carefully. Check whether the joints are loose, lubricated well, flexible, abnormal wear and tear, and find out the problems and deal with them in time.
(2) The mixing station should listen to and think carefully when it is moving and turning, and make sure that every kind of sound, if any, is abnormal. We should find out the reasons and deal with them properly.
(3) Be good at distinguishing various odors. If the oil temperature is too high, the discharging temperature is over the limit, the circuit and electrical appliances are burnt out due to short connection, the overheating caused by abnormal friction, and the electrical appliances and circuits are overloaded and heated seriously, they will emit different odors. Through different odors, some faults can also be predicted.
In short, the operator should pay attention to look at the face, through various sensations, with the help of different instruments, to clarify every abnormal change, careful analysis, identify the causes, find out hidden dangers. Because of the complex structure of the mixing station, there are many kinds of components, including electrical, gas control system, asphalt supply system, combustion system, metering system, dust removal system and so on. It is very difficult for an operator to be proficient in various parts in a short time, to accurately judge and eliminate all faults. Therefore, if we want to be an excellent operator, we should observe carefully, think diligently, summarize carefully and accumulate experience constantly.
Besides being proficient in equipment, operators should also have general knowledge of product quality control. That is to say, they are familiar with the temperature, asphalt-aggregate ratio and gradation of asphalt mixtures, and can make technical judgments of mixtures, analyze and solve the problems of mixtures in time.
(1) Temperature control of mixtures: The temperature of mixtures is one of the criteria for assessing the conformity of mixtures. Excessive or low temperatures are wastes and cannot be used. Therefore, how to control temperature is one of the basic skills that operators should possess. The factors affecting the temperature of mixture are the quality of fuel oil. If the quality of fuel is poor, the calorific value is low, and the combustion is not enough, it will cause unstable heating and low temperature of stone, and the residue after burning will remain in the mixture, which will seriously affect the quality of the mixture. If the fuel viscosity is too high, impurity content is more, water content is larger. The water content of raw materials is another factor affecting the temperature. The water content of raw materials is large and uneven. In the process of production, the heating temperature of stone is difficult to control. In addition, the technical condition of combustion system, the pressure of fuel pump and the amount of fuel injection are all related to the temperature of mixture. The wear, leakage and blockage of the combustion system make the components unable to maintain their original performance, resulting in lower system pressure, unstable fuel supply and poor atomization combustion effect, which seriously affects the mixing temperature. Therefore, experienced operators should be able to accurately judge the quality of fuel, the dryness and wetness of raw materials, and the operation of the combustion system. When problems are found, corresponding measures should be taken. Although the current mixing equipment has the ability of temperature automatic control, the temperature control lags because it needs a process to add or subtract the flame from the temperature detection to adjust the temperature. In order to ensure that there is no waste in stirring temperature mixing station, the operator should carefully observe the change rate of temperature, predict the change result of temperature in advance, and manually add or subtract flame or increase or decrease feed quantity to control the change of temperature, so that the change result does not exceed the prescribed range, thereby reducing or eliminating waste.(2) Mixture gradation control: Mixture gradation directly affects the performance of the pavement. If the gradation of the mixture is unreasonable, there will be some diseases on the pavement, such as large void ratio, small void ratio, permeability, rutting and so on, which will reduce the service life of the pavement and seriously affect the quality of the project. Therefore, the gradation control of mixtures is also one of the skills that operators must possess. The factors affecting the gradation of mixtures are: the change of raw material particle size, the change of sieve in mixing station, the range of measurement error, etc. The size of raw material particle directly affects the gradation of mixture. When the raw material changes, the operator should cooperate with the laboratory to fine-tune the production mix. The change of the hot material sieve in the mixing station is an important factor affecting the gradation of mixtures. If the sieve is blocked and the hot material sieving is inadequate, the gradation will become finer. If the sieve breaks, breaks, leaks and wears out of the limit, the gradation of mixtures will become thicker. The measurement error in the mixing station also directly affects the gradation. If the measurement error range is adjusted too large, the production mixing ratio will match the target. The ratio deviation is large, which seriously affects the quality of mixtures. If the adjustment of measurement error range is too small, it will increase the measurement time and affect the output. It will also make the measurement frequently exceed the limit and affect the normal operation of the mixing station. In a word, the operator should pay close attention to the changes of raw materials, check the screen regularly, find out the problems and solve them in time, and adjust the measuring range to the best state according to the characteristics of the mixing station and other factors. Think carefully about other factors affecting gradation, so as to ensure the mixture ratio.
(3) Control of asphalt-aggregate ratio of asphalt mixture: The optimum asphalt-aggregate ratio of asphalt mixture is determined by the gradation of aggregate and the content of powder. It is the fundamental guarantee of pavement strength and performance. Excessive or small asphalt content will cause different diseases of pavement.
Therefore, strict control of asphalt dosage is an important link in production control. In production, operators should pay attention to the following aspects:
In operation, the error range of asphalt metering should be adjusted as small as possible to make asphalt metering more accurate; the amount of additional powder is also an important factor affecting the optimum asphalt-stone ratio, so meticulous control should be taken for the metering of powder; according to the dust content of fine aggregate, the opening degree of induced draft fan should be adjusted reasonably so as to make the dust content in mixtures within the design range.
In modern construction, we must have advanced equipment to ensure the quality of the project. At the same time, we must have good operation technology to make the equipment give full play to its advantages. First-class equipment, first-class operation level, first-class management, first-class products, first-class quality. Only in this way can the project be completed on time, in good quality and smoothly.
Free consultation telephone for asphalt concrete mixing station: 4006-988-936