Constant Pressure Liquid Supply for Filling Machines
Introduction
Paste syrup products have always been important pharmaceutical products. With the continuous development of the market, the continuous growth of market demands, and the increasingly worn out and old equipment, the original production technology can no longer meet the market requirements for product quality and output. In order to further improve production efficiency and product quality, the pharmaceutical industry will introduce automatic filling machines into production and increase the capacity of the filling production line.
Problem analysis
The introduction of the filling production line liberated productivity to a certain extent and improved the product quality of the company. However, in the actual production process, it was found that although the filling machine saved manpower and material resources to a certain extent, there were still some problems such as uneven filling weight, declining product qualification rate and so on, which could not meet the product quality and qualification rate required by the company. At the same time, there are still some potential safety hazards, mainly reflected in the following three aspects.
1. The high position of the liquid medicine storage box in the filling production line makes it difficult for workshop workers to add liquid medicine, resulting in the waste of manpower and material resources.
2. The unstable liquid level in the liquid medicine storage tank leads to unstable filling quantity and high product unqualified rate. At the same time, manual inspection and rework are used, resulting in a waste of manpower and material resources.
3. The temperature of the liquid medicine is high, which makes it difficult for workers to operate during dosing, and easy to bring personal and production safety risks.
The production process of the imported filling production line: manual feeding, liquid medicine storage box and bottle sorting, canning, capping, labeling and finished products.
Equipment process and upgrading
The production process of the filling production line is to manually fill the liquid medicine into the storage box of the filling machine; inject the liquid medicine into the cleaned and sterilized medicine bottle through the filling machine, and screw the cap. After the label inspection, the product is finished. Among them, filling, bottle sorting, capping and labeling are all completed automatically by the production line, which has high accuracy in good quality. Charging and inspection are completed by manual operation. The inspection process is relatively simple, mainly to check the physical appearance such as product label and appearance uniformity. There are some problems in the charging process, mainly as follows:
1. The high position of the liquid medicine storage box brings production problems and potential safety hazards.
2. Improper operation or lack of operation awareness by operators leads to different liquid levels in storage tanks for a long time, which is also the reason for the high product unqualified rate.
The production and safety problems in the filling production line are caused by the low degree of automation in the filling process and the high position of the medicine storage tank. Therefore, the key to solving the problem is to realize the upgrading transformation from manual storage to automatic storage. The upgrading idea of filling production line is as follows.
The idea of upgrading the canning production line: Medicine tank 1, medicine tank 2 and medicine tank 3 are connected with the liquid supply pump together. After automatic material storage, they go to the medicine liquid storage box of the filling machine and arrange the bottles at the same time. Next, after canning, capping, labeling, the products are finished.
Solutions
1. Scheme principle
The key to upgrading the filling production line is to improve the filling link, from manual storage to mechanical automatic storage. Therefore, it is the most important and difficult problem to realize the transformation from manual operation to intelligent control. Through a week-long communication and discussion within the group, data search and field investigation in the workshop, the group members proposed to use pressure sensors to realize the dynamic control of the filling process.
A pressure sensor is installed on the original filling production line to control the quality of the liquid medicine in the medicine storage tank of the filling machine, so as to control a certain dynamic liquid height and complete the constant pressure filling in the whole filling process. The original manual feeding mode is replaced by the liquid supply pump to eliminate the potential safety hazard of the original production line. If the weight of the liquid medicine in the medicine storage tank of the filling machine exceeds the set range, the pressure sensor detects and outputs a signal to the control relay. After receiving the signal, the control relay converts it into an electric signal to reduce the liquid supply, and the frequency converter reduces the frequency to reduce or stop the liquid supply of the pump. On the contrary, if the weight of the liquid medicine in the medicine storage tank of the filling machine is lower than the set range, the pressure sensor will also detect and control the relay conversion signal, and the frequency converter will increase the liquid supply by the pump after frequency increases, so as to realize the dynamic control of the whole filling process. While eliminating potential safety hazards, product quality is ensured.
2. Plan implementation assumption
On the basis of determining the basic solution, the tentative plan of implementation is preliminarily determined, as shown in Figure 1.
Figure 1 Canning production line process
Improvement
Add liquid supply pumps instead of manually adding liquid medicine to eliminate potential safety hazards, as shown in Figure 2. The pressure sensor realizes the dynamic balance of the filling process, as shown in Figure 3. Through a one-month workshop site survey, equipment purchase and installation, and new process debugging, the process upgrade and improvement were completed. The process upgrade improves the automation degree of the filling production line and completely eliminates the potential safety hazard in the production process. See below for improved equipment.
Liquid supply pump: 1
Usage: Send the liquid medicine to the storage box.
Medicinal silicone tube for liquid supply: 80 cm
Usage: Used with liquid supply pump.
Pressure sensor: 1
Usage: installed in the medicine cabinet for storing liquid.
Pressure controller: 1
Usage: Set the upper and lower limits of liquid level and display the height of the liquid level.
Inverter: 1
Usage: Set parameters according to control requirements.
Stainless steel pipe: 10 m
Usage: Connect the storage tank and the medicine storage tank with the stainless steel pipe.
Control relay: 1
Usage: Using the signal of the pressure controller to control the fluid supply of the frequency converter.
Results
1. Production efficiency
The improvement of the process further improves the automation degree of the paste-frying production line, and the improvement of the pass rate of the first inspection reduces the rework rate and labor cost. Improve the total production efficiency while avoiding the waste of manpower and material resources, so that the production plan can be successfully completed, which is more in line with the workshop image of good manufacturing practice and better meets the market demand.
2. Economic effect
The improvement of the process improves the pass rate of the first inspection and reduces the waste of human resources caused by the loss of packaging materials and rework. From before implementation to now, the qualified rate of the first inspection of the filling process has reached 99.78%, which is about 10% higher than before. According to the annual production plan, the labor cost and the loss of packaging materials can be reduced annually, equivalent to 1.5 million yuan.
3. Safety effect
The upgrade strategy of mechanical feeding and automatic control completely solved the hidden safety problems of the high position of liquid storage filling, difficult filling operation and high operation risk coefficient, and implemented the company's people-oriented principle and belief of comprehensive preparation before risks.