The application of automatic fire detection weighi

Application of automatic weighing scale in petrochemical quantitative packaging production line

with the in-depth development of cost accounting, potential tapping and efficiency improvement in PetroChina Daqing Petrochemical Company, through demonstration, it is proposed to improve the measurement and sampling inspection means of quantitative packaging products. Install automatic weighing scale on the packaging production line and equip it with automatic weighing system to realize closed-loop automatic control of packaging and automatic weighing, so as to maximize the benefits of quantitative packaging products

I. automatic weight checking system

automatic weight checking scale is a kind of weight checking equipment with high speed and high accuracy, which can be integrated with various quantitative packaging production lines and conveying systems. It is mainly used to detect whether the product weight is qualified and whether it is in the package. 1. Automatic zeroing: the purchase price of Tianjin steel pipe scrap is reduced by 40 yuan/ton; Guangxi Wuzhou Yongda scrap purchase price fell by 20 yuan/ton; Anhui Lixin special steel scrap purchase fell by 20 yuan/ton. The computer received the instruction to start the experiment, whether it lacked parts, and provided feedback signals to adjust the feeding equipment (as shown in Figure 1)

the automatic weight checking system is mainly composed of weighing table, transmission belt, display controller and elimination device. The knockout device is generally air blowing type and push rod type

II. Main functions of the automatic weight checking system

1. Technical indicators

according to the characteristics of the process flow of quantitative packaging products, the automatic weight checking system is selected to be equipped in the high-pressure polyethylene quantitative packaging line. Installation position of automatic weighing scale: it is installed at the position after the bagged polyethylene products enter the conveyor belt and pass through the left and right straightening mechanism. Disconnect and improve the original conveyor belt. When installing the automatic weighing scale, it is necessary to ensure that the conveyor belt of the weighing scale is in the same plane with the original conveyor belt, so as to ensure that the bagged polyethylene can pass through the automatic weighing scale smoothly and accurately detect the weight of the bagged polyethylene

installation position of the culling device: downstream of the automatic weighing scale of the conveyor belt, try to be close to the automatic weighing scale, because the horizontal length of some conveyor belts is limited. The knockout device is push rod type (reversible). Specification of automatic weighing scale: the length of the conveyor belt is 1200mm, the width is the same as the original conveyor belt, and it is equipped with a transmission motor. A digital sensor is used for weighing

technical parameters of automatic weighing scale: measuring range: 30kg, which should be selected according to the actual bag capacity, and the polyethylene is 25kg/bag; Error setting value: ± 5g, positive and negative values can be set respectively, which is convenient for setting the difference between positive and negative errors, and is conducive to accurately controlling the packaging volume; The throughput should match the original packaging. Weight detection and control: the automatic weight detection scale will process the dynamic weight signal to save, display, output and alarm. At the same time, if there is no graphene flagship company, this shoe will feed back the error control signal to the quantitative packaging scale control and adjustment system, adjust and control the quantitative packaging scale in real time, and output the out of tolerance control information to the rejection device

2. Application functions

various functions of the automatic weight check scale fully meet the characteristics of enterprise automatic production and the needs of measurement management

. In addition to displaying the dynamic weight check, there are multiple standard weight partitions, which can store 100 product data. Hierarchical password protection, statistical weight check data by shift, product type, product batch, time period, qualified and unqualified, and positive and negative allowable differences can be set respectively, It can control the packaging quantity well. The automatic weight inspection system feeds back the weight inspection information to the quantitative packaging control system in real time, and automatically controls the packaging volume in real time. The packaging bags that exceed the measurement tolerance will be automatically removed and an alarm will be given automatically. For earlier old production lines, when there are bags that exceed the measurement tolerance, the packaging actuator can be controlled to stop packaging and manually adjust the settings`

3. Precautions

because polyethylene and other packaging bags are purchased, it is found that the pressure testing machine with

is a widely used equipment in the past sampling inspection of quantitative packaging products. The tare weight of packaging bags in batches is different from the specified value. After the automatic weight inspection system is equipped, we must pay attention to this point. At the same time, we should also regularly or irregularly use standard weights to conduct sampling inspection of automatic weight inspection scales, Vertical technology to ensure the accuracy of automatic weighing scale

III. application and benefits

with the implementation of the 600000 ton/year ethylene expansion project, automatic weighing scales and automatic weighing systems have been installed in two production lines of 200000 ton/year high-density polyethylene, and have passed the acceptance

the package of urea is 40kg/bag, the national production standard stipulates that the measurement tolerance is ± 400g, and the company's internal control management stipulates that the measurement tolerance is_ ±200g。 The packaging of high-density polyethylene, low-density polyethylene and polypropylene is 25kg/bag. The measurement tolerance specified by the national quantitative packaging product management regulations is ± 25og, and the measurement tolerance specified by the company's internal control management regulations is ± 200g

after equipped with automatic weighing scale, the measurement tolerance of each bag is controlled between ± (50 ~ 100) g. The two high-density polyethylene production lines in the whole year can pack at least 800 tons of products. According to the current market price, it can create more benefits of more than 3million yuan per year. The annual output of quantitative packaging products such as urea, high-density polyethylene, low-density polyethylene and polypropylene is nearly one million tons. If all production lines are installed with automatic weighing scales and automatic weighing systems, the annual benefits can be increased by tens of millions of yuan

mouth: planning and operation Office of PetroChina Daqing Petrochemical Company Yang Peimin, Wang Yu, Dou Yan, Zhang benpeng

-- China Metrology