Views: 268 Author: Site Editor Publish Time: 2021-07-01 Origin: Site
Most feeds, such as poultry feed, livestock feed, fish feed, etc., are powdery and granular feedings that flow poorly and are easy to digest. In order to ensure the accuracy and speed of the control system, the feeding devices of quantitative weighing and packing machines used for finished product packaging in the past mostly adopt direct feeding, double screw feeding or double vibration feeding. Due to poor fluidity of feed, inertia of screw feeding or vibrating feeding machine, and uneven material transportation, it is difficult to control the dynamic precision of quantitative multihead weigher packing machine stably. In the three-level control mode of frequency converter, double helix feeding or double vibration can be changed into single belt feeding, which not only reduces the production cost of equipment, but also ensures the integrity of finished products.
At present, automatic quantitative weighing filling machines produced at home and abroad are mainly divided into bucket type and bucket-free type according to the form of measuring bucket; According to the weight form, it is mainly divided into net weight type and gross weight type, but most of automatic weighing and packing machines adopt modular design ideas. The designed prototype uses bucket-less gross weight to weigh, which is mainly composed of storage bin, belt feeder, transition device, cutting device, weighing unit, bag clamping device, pneumatic part, sewing part, finished product conveying part and electrical control unit.
The maximum weighing capacity of the semi automatic weighing and filling machine is 25 ~ 100 kg; The weighing speed is 6-10 bags/min; The weighing accuracy is 0.5% ~ 1.0%; Average power consumption is about 5kw.
There are many kinds of feeding parts, such as straight feeding, spiral feeding, scraper feeding, vibrating feeding and belt feeding, etc. Different ways can be selected according to different materials, and the suitability of this part directly affects the speed and accuracy of quantitative weighing and filling machine. Due to the particularity of feed industry process, in order to overcome the problems of funnel-type material blockage, material breakage caused by spiral or scraper, and serious dust pollution caused by vibration feeding, we choose belt feeding in this equipment.
The weighing part of automatic weight and packing machine is mainly composed of weighing hopper, weighing sensor, weighing display controller, etc., which can complete the accurate measurement of materials and send the control signals required by the control system: over-and under-quantity signals, preset advance signal, advance signal, target value signal, 4 ~ 20mA analog signal and standard RS232/485 signal.
The entrainment part is round, which can ensure the tightness of weighing and bagging machine after clamping the bag, and has an exhaust port to discharge the dust and air in the bag in time. This part mainly relies on pneumatic actuators to complete its actions.
Put the weigh filler packaging machine in automatic working state, turn on the automatic button, start the belt feeder to carry out primary feeding, when the preset advance is reached, the weighing unit sends a signal, and the frequency converter switches to the secondary feeding mode; When the advance amount is reached, the weighing unit sends a signal, and the frequency converter switches to the three-stage feeding mode. When the set target value is reached, the cutting hopper is closed, the bag is loosened and bagged, and the multihead weigher machine’s system automatically switches to the power frequency state for the next cycle.