Inspection of Liquid Filling Machines
According to relevant requirements, in the inspection of liquid filling machines, it is necessary to detect the appearance, coordination performance, control performance, filling accuracy, filling capacity and qualified rate of the equipment, so as to fully understand the running state and performance of liquid filling machines. Common problems in the process include out-of-tolerance measurement errors, uncoordinated conveying actions, etc. However, due to various types of liquid filling machines and differences in equipment structures, the performance and specific reasons for the problems are also different, so targeted analysis must be carried out, and effective solutions can be taken.Basic Inspection of Liquid Filling Machines
1. Appearance Inspection
Firstly, check the measuring unit of the filling machine. Different types of filling machines have different measuring units, including G, KG, ML and L. Secondly, check the nameplate on the filling machine, which must clearly indicate the model, full name, serial number, filling quantity, filling capacity, measuring unit, filling accuracy, delivery time and manufacturing unit of the filling machine. Then it turns to the startup check. After startup and operation, check the conveying action of the filling machine to see if it is in normal coordination. Finally, check the actual filling capacity of the filling machine. Start the machine for more than 3min, and check whether the actual filling capacity of the filling machine is consistent with the rated filling capacity.
2. Temperature Detection and the Inspection of Temperature Error Correction System
During the operation of the liquid filling machine, the actual filling amount is influenced by the temperature of the liquid material. The setting of temperature and density during filling cannot be based on the actual temperature and density of liquid material, otherwise, the filling machine will fill according to the actual temperature of liquid material. Once the temperature of the material changes, the filling amount error will be out of tolerance. Because the bulk density of liquid materials is closely related to the temperature change, the bulk density increases when the temperature increases, and decreases when the temperature decreases. Therefore, although the volume has not changed, the filling quality has already experienced errors. In view of this situation, in the verification process, it is necessary to check the temperature detection and temperature error correction system of the filling machine to ensure its normal operation, which can be adjusted in time according to the actual temperature of the liquid material during filling to eliminate the influence of temperature change on the filling quantity.
3. Measurement Accuracy of Filling Capacity
There are three main aspects to pay attention to about the accuracy of filling capacity measurement. First, check the sensitivity of the top tank level gauge to ensure that it meets the operation standard of the filling machine, otherwise it needs to be adjusted; The second is to check the film length of the filling machine to ensure its consistency, otherwise it needs to be corrected. The third is to check the reflux pressure of the material equipment in front of the filling machine to ensure that it is in a stable state without obvious fluctuation, otherwise it needs to be adjusted and optimized.
4. Check the Accuracy of the Filling Flow
The accuracy check of filling flow mainly focuses on the following aspects. First, check the top tank liquid level and liquid level controller to see if they are running normally. Generally speaking, if the top tank liquid level and liquid level controller are normal, the fluctuation of liquid level should be within a reasonable range without abnormal fluctuation. The second is to check the flow control valve, with emphasis on checking whether the set air pressure is reasonable and whether there is fluctuation. If the set air pressure is abnormal and abnormal fluctuation occurs, it is necessary to find out the reason in time and reset the air pressure of the flow control valve. The third is to check the material return pressure of the sterilizer. Under normal circumstances, the material return pressure is basically constant during the operation of the sterilizer, with fluctuation less than 10% and performing regularly. The fourth is to check the air content in the filling liquid. If the air content in the filling liquid exceeds the standard range, the foam will be generated in the filling liquid. Fifth, check the filling pipe and the filling valve joint. Specifically, check whether there is any foreign matter or blockage in the filling pipe, and handle it in time if necessary. Check whether there is leakage at the joint position of the filling valve and uneven bag cutting size, and adjust and deal with it in time if necessary.
5. Other Matters Needing Attention
First, after the liquid filling machine is started up, if it is necessary to check the filling quantity, it is generally necessary to let the equipment run for a period of time for inspection. The main reason is that the filling quantity at the initial stage of a startup may not be stable enough, which will affect the judgment of inspection results. Second, during the operation of the filling machine, the liquid level of the top tank needs to be kept relatively constant, so it is important to ensure that the sensitivity and accuracy of the liquid level gauge meet the equipment operation standards. Third, during the operation of the filling machine, it is necessary to periodically check the filling quantity, and make timely adjustments when any abnormality is found. Fourth, filling machines with different models, structures and working principles need to seal the filling quantity adjusting equipment or take other protective measures after verification, so as to avoid changing the filling quantity artificially. The adjustable range of the filling quantity needs to be clearly defined after verification. Fifth, the positioning system of the filling quantity adjustment equipment needs to run well to ensure that it can be positioned quickly when adjusting the filling quantity. If the filling machine has multiple gears, it needs to be re-verified when adjusting gears, and cannot be put into use directly after debugging. Sixth, the inspection standard instruments used in the process must be processed within the inspection cycle to ensure that the inspection standard instruments have good performance and high reliability, especially those with high precision such as densimeter and balance.
Common Problems in the Inspection of Liquid Filling Machines and Its Solution measures
Common problems in the inspection process of liquid filling machines are mainly out-of-tolerance measurement errors, uncoordinated tree hole movements and communication errors, etc. Because there are various types of liquid filling machines, and there are differences in equipment structures and working principles, even for the same problem, the performance of different equipment may be different, so it is necessary to analyze specific problems. The following is an analysis of the common problems in the inspection process of liquid filling machines.
1. Measurement Error Out-of-tolerance
The problem of out-of-tolerance of measurement error is simply that the measurement error of liquid filling machines exceeds the allowable range, which is the most common problem in the inspection process. Different equipment types have different reasons for out-of-tolerance of measurement error, and different filling liquids have different reasons for out-of-tolerance of measurement error. The following is a detailed analysis.
1.1 Out-of-tolerance Measurement Errors of Different Filling Machines and Solutions
(1) Self-flow constant volume filling machines: The self-flow constant volume filling machine is a liquid quantitative filling machine with a relatively long history. There are three main reasons for its out-of-tolerance measurement error. First, the equipment is dripping. Second, there is an insufficient fluid replacement in the filling process. Third, the error of the measuring cup is too large. Based on this, the problem of out-of-tolerance measurement error of self-flow constant volume filling machines can be solved from three aspects. First, check the equipment pipeline to see if there is any dripping, then repair the pipeline or replace the accessories to prevent liquid dripping. Secondly, if there is no dripping of the equipment, it is necessary to check the liquid inlet flow rate of the filling machine and the liquid level of the top tank. If it is found that the liquid inlet flow rate of the top tank decreases, it is necessary to increase the liquid inlet flow rate in time to ensure that the liquid level of the top tank is kept at a normal level and avoid the situation of insufficient liquid replenishment. Finally, if there is no shortage of rehydration, it is necessary to check the measuring cup to see if its accuracy meets the requirements. If the measuring cup error is too large, it needs to be replaced in time to control the error within a reasonable range. It should be noted that there may be two or even three kinds of the above-mentioned problems at the same time, so it is necessary to check these three aspects according to the procedures when dealing with this problem.
(2) Volumetric filling machines: There are three main reasons for the out-of-tolerance measurement error of volumetric filling machines. First, the overflow of filling machines leads to excessive measurement error. Second, the metering pump of the filling machine is unqualified, which leads to the inconsistency of the filling quantity. Third, the temperature change of liquid materials leads to excessive measurement error. In view of the above problems, three measures can be taken specifically, one is to increase the filling speed, which is mainly realized by adjusting the running speed of the stepping motor, that is, the method of being fast before being slow, to control the filling error and avoid an excessive error. Secondly, the step number of the stepping motor is artificially adjusted according to the filling head of the filling metering pump, so as to reduce the difference of filling quantity of each filling head, and then effectively control the filling quantity error. The third is to check the temperature detection and temperature error correction system of the filling machine to ensure its normal operation, which can be adjusted in time according to the actual temperature of the liquid material during filling, so as to eliminate the influence of temperature change on the filling quantity.
(3) Cylinder-piston filling machines: The problem of out-of-tolerance measurement error in cylinder-piston filling machines is mainly due to the difference of cylinder diameter, which leads to the deformation of the diaphragm due to the pressure of filling liquid, thus resulting in out-of-tolerance measurement error. In addition, if the viscosity of the filling liquid is too high, it may also lead to the problem of out-of-tolerance measurement error. In order to solve the above problems, first of all, we can measure the spacing of clapboards regularly during the operation of the filling machine, and adjust the clapboards with too large or too small spacing in time, so as to control the measurement error. Secondly, if the viscosity of the filling liquid is high, the running speed of the stepping motor can be adjusted correspondingly during filling, so as to effectively control the filling error.
1.2 Out-of-tolerance Measurement Errors of Different Filling Liquids and Solutions
(1) Foam liquid: Although foam liquid belongs to the category of liquid, it is different from conventional liquid, such as carbonated drinks and beer. When the foam liquid is filled, the transportation power mainly depends on the way of being pressed. When the foam liquid enters the filling machine, the unstable pressure of the foam liquid may cause the carbon dioxide in the foam liquid to escape, which will further affect the filling effect. In order to solve this problem, we can try to adopt frequency conversion control technology to ensure that the liquid pressure of foam liquid is kept relatively constant after entering the filling machine, and reduce the carbon dioxide escape, so as to effectively control the influence of the tubular effect.
(2) Hydrocarbons: Hydrocarbons are special. This kind of liquid is greatly affected by temperature during filling, and its volume will change obviously when the temperature changes, which will lead to excessive measurement error. To solve the above problems, it is necessary to calculate the filling quantity accurately first, and then according to the filling temperature, calculating the volume change of hydrocarbons, so as to control the volume of hydrocarbons by reasonably controlling the filling temperature during filling, and ensure the accuracy of filling quantity. Generally, if the error between the filling temperature and the standard temperature does not exceed 5℃, the problem of out-of-tolerance measurement error will not occur.
2. The Problem of Uncoordinated Conveying Actions
The problem of uncoordinated transportation mainly refers to the abnormal transportation between the filling head and the packer of the filling machine, which affects the filling quality and filling rate, which is also one of the common problems in the inspection process of the quantitative filling machine for liquid materials. The problem of uncoordinated action between the filling head and the packaging container in the filling machine is probably caused by problems in the rolling bearing, gearbox and other parts. It is necessary to add grease to the rolling bearing and gearbox to reduce friction. Generally speaking, these two parts need to be disassembled once a year and greased, while the gear lifting parts need to be disassembled once every three months and greased to reduce parts wear and prevent parts from rusting. In addition, after the equipment is used, it needs to be cleaned as a whole. Impurities, dust and others alike on the surface and parts should be clear, so as to ensure the normal operation of the equipment, without abnormal movements and noises.
3. Communication Error
In the inspection process of liquid quantitative filling machines, the frequency of communication errors is lower than the above two problems. Generally, it is mainly caused by factors such as strong interference sources in equipment accessories or looseness of communication equipment joints. In view of the above problems, firstly, it is necessary to investigate the environment around the filling machine to check whether there are strong interference sources, such as strong magnetic field, high-frequency current, etc. If there are strong interference sources, take timely measures, such as removing strong interference sources or installing anti-interference equipment. If the surrounding environment is normal, start to check the communication equipment to see if the connector is loose and if so, take fastening measures in time.
Conclusion
To sum up, in the process of filling machine inspection, problems such as out-of-tolerance measurement error, communication error and abnormal conveying action are relatively common. Technicians need to specifically analyze the causes of related problems according to the actual situation and then deal with them pertinently, so as to keep the filling machine in a good running state, ensuring the filling quality and protecting the interests of enterprises.