CN111123879A - PLC automatic blending control system for refractory material - Google Patents

Abstract

The invention relates to a PLC automatic batching control system for refractory materials, which consists of a WinCC system, a PLC control system, a weighing system and a vibration feeding system. The WinCC system realizes real-time monitoring of the whole batching process. The parallel blanking mode is controlled by the PLC, and the production efficiency is improved. The weighing system is provided with secondary weighing, so that the weighing is more accurate. The vibration feeding system is provided with different vibration feeders according to different powder and granular materials, so that equipment faults are reduced, and maintenance difficulty is reduced.

Description

PLC automatic blending control system for refractory material

Technical Field

The invention belongs to the field of refractory material production and processing, and particularly relates to a PLC (programmable logic controller) automatic batching control system for refractory materials.

Background

The batching process of a refractory plant is basically divided into three main categories: the first type adopts manual batching, the batching automation degree is low, the labor intensity of workers is high, and the working environment is poor; the second type adopts a traditional relay contactor control system, the automation degree is improved, but only the batching control of a fixed formula can be completed, the batching process cannot be changed according to the change of the formula, and the control mode is not flexible enough; and the third type adopts a PLC control system to complete the formula control and management of the refractory materials, can change the batching process according to different formulas, then weighs different raw materials and successively adds the raw materials into a storage bin for mixing, and realizes automatic batching.

At present, the first type of artificial ingredients are already eliminated, and the second type of relay contactor control system cannot meet the trend of product diversification and formula complication due to fixed formula and is gradually eliminated. The third type of PLC control system is the mainstream batching process of the refractory plant at present, but the automation degree is not high, the batching is performed in a serial mode (each raw material sequentially goes onto a material conveying vehicle or a belt conveyor), and the production efficiency is not high. Meanwhile, the raw materials of the fire-resistant factory contain powder and granular materials, and the existing batching process basically and uniformly adopts electromagnetic vibration feeding without distinction. In addition, some processes set the weighing sensor and the vibration feeder below the material bin, and the material is fed and weighed while vibrating, so that the vibration and the weighing cause great interference, and the metering is not accurate enough.

Disclosure of Invention

Aiming at the problems, the invention provides a novel PLC (programmable logic controller) automatic batching control system for refractory materials, which can realize high-precision control and monitoring of any quantity of batching formulas, improves the automation degree and the production efficiency of the system, sets different feeding modes aiming at powder and granular materials, and simultaneously realizes double metering to ensure that the weighing is more accurate.

The system consists of a WinCC system, a PLC control system, a weighing system and a vibration feeding system, and a control function block diagram of the system is shown in figure 1.

WinCC is host computer software, uses the process monitoring system of 32 bit technologies, possesses the characteristics of preemptive multitask, is suitable for the quick response to the process incident, can very conveniently generate the human-computer interface, establishes complete process monitoring solution, monitors the production field in real time, dynamically displays the batching weight, automatically monitors whether the system normally operates, and the running state of the whole batching production line is clear at a glance. The system records the formula of the fire-resistant product in a note file mode, and reads and writes the formula file by using a C language script (standard ANSIC) built in WinCC, so that the functions of calling, storing, modifying and the like of formula data are realized. The system can also record and print the batching results of each time, generate an alarm and the like.

The PLC control system completes the conversion of the measured value of the hopper scale, the monitoring of the bin position, the system alarming, the walking, the positioning and the material receiving of the material conveying trolley, the voltage control of the electromagnetic and motor vibration feeder and the like, and is the core of the whole control system. The parallel mode is adopted in the unloading of each feed bin, the material of hopper balance, and the unloading is simultaneously practiced thrift the unloading time, improves production efficiency. The system not only can complete automatic control, but also can realize manual control of an upper computer and manual control on site.

The weighing system is the most important link in the control of the ingredients, and the precision and the reliability of the weighing system determine the quality of the ingredients. The system is designed for secondary weighing, wherein a hopper scale is used for the first time, and the materials enter the hopper scale from a storage bin according to a formula to be weighed for the first time; the second time is that the material transporting trolley weighs, and the material transporting trolley is used for transporting materials, and the electronic scale is additionally arranged at the bottom of the material transporting trolley, so that the raw materials are weighed again and rechecked when entering the material transporting trolley from the hopper scale, the metering accuracy is ensured, and whether the hopper scale and the metering function of the whole system are in a normal state or not can be checked. The vibratory feeder of the hopper scale is closed when the hopper scale receives the material and weighs, so that the vibration is reduced as much as possible to ensure that the weighing is accurate, the vibratory feeder of the trolley is also closed when the material receiving trolley receives the material and rechecks the weight, meanwhile, the weighing terminal selects the weighing device with the functions of digital filtering and high-quality noise filtering, a stable weight value can be obtained very quickly, the A/D conversion rate reaches 300 times/second, the display rate is 20 times/second, and the control precision requirement of a batching system is met.

The vibratory feeding system is characterized in that two vibratory feeders, namely an electromagnetic vibratory feeder and a motor vibratory feeder, are designed according to different powder and aggregate, the electromagnetic vibratory feeder is arranged below the powder bin, the powder hopper scale and the material conveying trolley, and the motor vibratory feeder is arranged below the aggregate bin and the aggregate hopper scale. The PLC calculates the material quantity required to be transferred by each bin, the voltage of the electromagnet is controlled by a fuzzy control algorithm to realize the control of the feeding speed, so that the material flow on the feeder is changed and is close to and kept at the set feeding flow, and the requirement of quantitative feeding is realized.

The production line of the new system is schematically shown in FIG. 2, and the production process is as follows: the system adopts the form record unloading prescription of note book, during the unloading read note book prescription through host computer WinCC and descend controller PLC, controller PLC starts the unloading of the electromagnetic vibration feeder or the motor vibration feeder of feed bin according to the prescription value of giving down, the hopper scale below the feed bin measures the unloading volume, when the unloading volume is close to the prescription volume, controller PLC reduces the voltage of vibration feeder automatically, the unloading volume slows down, stops vibration unloading when reaching the prescription volume. The blanking of each bin is carried out simultaneously, and the blanking is independent and not interfered with each other. When the blanking of a certain storage bin is finished, the controller PLC controls the conveying trolley to travel to the position below the hopper scale, the electric gate valve and the vibratory feeder at the bottom of the hopper scale are opened, the raw materials in the hopper scale fall into the conveying trolley, the electronic scale at the bottom of the trolley rechecks the weight, and an error is given out timely. After the raw materials are completely discharged, the controller PLC controls the material conveying trolley to move to the position below a hopper scale for discharging the next material, the above operations are repeated until all the raw materials are discharged into the material conveying trolley according to the formula, the material conveying trolley is controlled to move to the position above the mixing bin, an electric gate valve and a vibration feeder at the bottom of the trolley are started, all the raw materials are discharged into the mixing bin to be mixed, and the refractory material is further generated. The control system can monitor the running state of the system in real time, when the contact of the control device does not act or the stock level of the stock bin reaches the lower limit, the system can automatically generate an alarm, and an alarm signal can be relieved through an upper computer WinCC interface.

The PLC automatic batching control system for the refractory material has the following advantages:

(1) the system adopts a batching control system consisting of a notebook formula, an upper computer WinCC and a lower computer PLC, can complete high-precision control and monitoring of any quantity of batching formulas, and has high automation degree.

(2) The material conveying trolley is separated from the hopper scale, each bin and the hopper scale work in parallel, the material conveying trolley preferentially runs to the position below the hopper scale where the discharging is finished firstly, the existing serial material proportioning mode is overcome, the whole material proportioning time is determined by the bin with the slowest discharging, the whole material proportioning time is shortened, and the production efficiency is improved.

(3) The raw materials comprise powder and granules. The electromagnetic vibration frequency is high, the amplitude is small, but the maintenance is inconvenient, and the electromagnetic vibration frequency is suitable for feeding powder; the motor vibration frequency is slightly lower, but the amplitude is larger, and the later maintenance is simpler, is fit for the aggregate feed. This production line sets up different vibratory feeder according to the difference of powder and aggregate, reduces equipment failure rate and reduces the maintenance degree of difficulty.

(4) Weighing adopts a dual metering system, and vibration feeding and weighing metering are respectively carried out, so that the metering accuracy and reliability are ensured.

Drawings

Fig. 1 is a control function block diagram of a control system.

FIG. 2 is a schematic view of a production line of the control system

1-a powder bin; 2-electromagnetic vibratory feeder; 3-powder hopper scale; 4-a pellet bin; 5-motor vibration feeder; 6-granule hopper scale; 7-transporting the material trolley; 8-a mixing bin; 9-trolley rail; 10-a stock bin support lug; 11-beam.

Detailed Description

The invention will be further described with reference to fig. 1 and 2.

As shown in the figure 1, an upper computer WinCC reads a notebook formula and downloads the notebook formula to a controller PLC, the controller PLC controls a raw material bin position according to the formula, a hopper scale weighs the raw material bin position, a material transporting vehicle runs, receives materials, unloads materials, vibrates the materials and the like to realize normal operation of production, and the operation condition is fed back to the upper computer WinCC, so that abnormal alarm occurs. For a refractory material, 4 raw materials are needed, wherein the codes are A, B, C and D respectively, A and B are granules, C and D are powder materials, the ratio is 1:2:3:4, and the specific production line is schematically shown in FIG. 2. The raw material A, B is hoisted into the grain bin by an electric hoist, and the raw material C, D is fed into the powder bin. And (4) inputting a formula by the upper computer and starting batching. A. B, C, D the electric gate valve of feed bin bottom is opened simultaneously, and the vibratory feeder starts the unloading simultaneously, and the hopper balance of each feed bin lower limit weighs the unloading volume according to the prescription requirement, when the unloading volume reaches the 80% of prescription requirement, slows down the unloading speed through the converter regulation, stops vibration unloading after reaching the weight requirement, closes feed bin bottom valve. The blanking is finished firstly, the material conveying trolley runs to the lower side of the hopper scale A immediately to receive the material, the bottom valve of the hopper scale is opened, the motor vibration feeder starts the blanking, the electronic scale of the trolley rechecks the weight and gives a warning if the problem exists, and the motor vibration feeder vibrates until the blanking is finished without slowing down. After the blanking of the hopper scale A is finished, the material conveying trolley is immediately moved to the position below the hopper scale B for finishing the blanking of the second time, the operation of the hopper scale A is repeated, the material is conveyed to the position below the hopper scales C and D again, the material is conveyed to the position above the mixing bin after the material is completely conveyed, the bottom valve is opened to start the vibratory feeder to discharge the materials, and the batching process is finished. The control system can monitor the running state of the system in real time, when the contact of the control device does not act or the stock level of the stock bin reaches the lower limit (10%), the system can automatically generate an alarm, and the alarm signal can be relieved through an upper computer WinCC interface.

Claims (1)

1. The utility model provides a refractory material PLC automatic blending control system, its characterized in that it comprises WinCC system, PLC control system, weighing system and vibratory feeding system, and each feed bin unloading and hopper balance connect the material to adopt parallel mode, and hopper balance and fortune material dolly secondary are weighed, and the vibratory feeding system sets up electromagnetic vibration feeder and motor vibration feeder respectively according to the difference of powder and aggregate.

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