CN111928565A

CN111928565A - Water adding method and intelligent water adding system for sand cooler of foundry plant

Info

Publication number: CN111928565A
Application number: CN202010806506.7A
Authority: CN
Inventors: 于彦奇
Original assignee: Ma'anshan Haisenkong Electric Co ltd
Current assignee: Ma'anshan Haisenkong Electric Co ltd
Priority date: 2020-08-12
Filing date: 2020-08-12
Publication date: 2020-11-13

Abstract

The invention discloses a water adding method and an intelligent water adding system for a sand cooler in a foundry, wherein the water adding method comprises the following steps of detecting the humidity C1 and the temperature T1 of sand at an inlet of the sand cooler, detecting the humidity C2 and the temperature T2 of the sand at an outlet of the sand cooler, calculating the water adding amount according to the detected humidity, temperature and sand throughput, and performing distributed water adding, wherein the water adding amount calculation formula is as follows: w is Wen + Wm, wherein W is the total water addition amount; we is the amount of evaporated water, and the temperature compensation coefficient is multiplied by Ws from T1 to T2; wm is the amount of moisturizing water, and Wm is (C2-C1) multiplied by Ws; ws is the sand throughput. The intelligent water adding system is a system matched with the method. The system and the method apply sensor physical perception and intelligent control to form a self-adaptive system, so that the used sand is changed from a physical state with an inlet changing into a physical state with an outlet tending to be constant in the continuous treatment process, and the requirements on the temperature and the humidity of the used sand are met: the outlet sand temperature is less than 50 ℃, and the humidity is approximately equal to 2.0 percent.

Description

Water adding method and intelligent water adding system for sand cooler of foundry plant

Technical Field

The invention relates to the technical field of casting sand treatment, in particular to a water adding method and an intelligent water adding system for a sand cooler of a foundry.

Background

The green sand is prepared by mixing quartz sand, bentonite, coal powder and water. Bentonite, also known as montmorillonite, is a natural mineral substance which can expand into paste when meeting water, has good cohesive force, can expand to 20-30 times in volume, can replace starch as a binder due to good water-absorbing expansion performance and dispersibility, and is widely used in foundry sand.

In the tidal sand processing production line equipment, a sand cooler plays a role in humidifying and cooling old sand. The humidifying and cooling is the process of increasing water and reducing temperature of high-temperature and low-humidity used sand after shakeout through a sand cooler in the recycling process, and the technical requirements of the cooler in China generally meet the passing capacity, the sand temperature is reduced to 45 ℃ and the humidity is increased to 2%.

Humidification and cooling are important steps in the treatment and control of foundry sand, and are used for carrying out logic control on the sand amount, the sand temperature, the water adding amount, the distribution and the dedusting air amount, so that the method is the most complex and the highest realization difficulty is achieved. The purpose of humidifying and cooling is to activate the residual active bentonite in the used sand as soon as possible and to reach the optimal use temperature of the sand mold. The humidifying and cooling are realized through a cooler, a large amount of water is evaporated (the residual is less than 0.2 percent) under the influence of high-temperature molten iron on the molding sand surface after casting, the sand temperature is increased (the temperature is up to 130 ℃), and the used molding sand after shakeout reaches the sand cooler through a sand return belt and a multi-angle sieve to finish humidifying and cooling.

One of the purposes of humidification is to moisten the used sand because it also contains a certain amount of activated bentonite and the surface of the facing sand is dried at high temperature. The bentonite has small granularity, the water absorption process is a moistening process, a certain period of time is required, the surface of the sand needs to be moistened to be better combined with a binder, and the water diffusivity during sand mixing is also enhanced, so that the active bentonite remained in the used sand is expected to be activated before sand mixing and participate in the binding and expansion action of the sand mould, water addition is required to be carried out at least 2-4 hours before sand mixing, namely the water addition on a cooler or a sand return belt is used for moistening, and the process requires that the water content of the used sand reaches 2%!

The second purpose of humidification is to cool down, the high temperature of used sand is extremely harmful to clay sand casting: 1) the instability of the water content of the molding sand is caused, the instability of compaction rate is further caused, the defects of the sand mold such as cracking, mold sticking, sand clusters and the like are formed, and the rejection rate is directly increased; 2) the sand temperature is too high, and the casting often has the defects of pinholes, impurities, sand washing, rough surface and the like; 3) the high temperature causes the water to condense and suck the powder and is adhered to the inner wall of the cooler, the sand warehouse, the bucket elevator and the belt, thus causing the difficulty of sand conveying. Therefore, the sand temperature is generally controlled below 50 ℃.

The most effective method for cooling is to add water, take away the surface heat of the used sand through the evaporation of water, and how to effectively promote the high-efficiency evaporation of water is one of the main problems to be solved by the sand cooler, the existing fluidized bed and the double-disk cooler are the main devices for humidifying and cooling in the sand treatment, and 3.5% of water needs to be evaporated when the temperature of the sand at 100 ℃ is reduced to 50 ℃. No matter which kind of cooler still undertakes the function that the sand was carried, add water too much, have the danger of "sticking the bed", add water too little and then the sand temperature can not drop, therefore the water control of sand cooler and add the water method and be the key technology of humidification cooling, industry requires at present that large molding sand treatment equipment must be equipped with the cooler and accomplish humidification cooling, reach sand temperature and drop to 50 ℃, moisture keeps below 2%, only the river cloudy three cast can reach through using our water system of adding in the current domestic brand, other few can reach this index requirement.

In the sand cooler, the treatment process of the boiling bed type cooler is continuous, sand passes through a cooling bed bottom plate like flowing water, air-permeable micropores are formed in the bed bottom plate, an air blower blows air into an air chamber below the bottom plate, the air enters the cooling chamber through the micropores of the bottom plate, meanwhile, the cooling bed is a vibrating conveyor, and the sand passes through the cooling bed and is in a boiling flowing water type. The main means for completing the humidifying and cooling functions is to add water and air draft, the added water is evaporated when meeting boiling hot sand, the heat of the sand is taken away to cool, the air draft takes away the high saturated vapor, the air blown in by the air draft provides the environment for continuous evaporation, and certain moisture in the sand is guaranteed after evaporation and cooling. The used sand return temperature of normal continuous operation is generally about 100-130 ℃, the moisture is almost zero, the sand is continuously sprayed with water, evaporated and sprayed with water when passing through the bottom plate of the sand bed, and the temperature of the sand is reduced from the surface inwards to the required 50 ℃; whereas the used sand humidity remained 2% after cooling. When the boiling bed type sand cooler is used, once too much water is added, if the humidity is more than 2.2%, a 'sticky bed' appears, residual bentonite and fly ash in old sand are muddy when meeting too much water, micropores on a bed bottom plate of the boiling bed are blocked, and the normal operation of the cooler is influenced, which is a problem faced in all foundries. The method is characterized in that an evaporation area and a humidification area are designed in a water adding system of the cooler in the continuous water adding process, the evaporation area is divided into a plurality of times of water adding, the water adding amount in the evaporation area is required to ensure that water is fully evaporated, if too much water is added into a first row of nozzles, the water evaporation is inhibited on the contrary according to the evaporation principle, and a sticky bed is easy to appear, and the humidification area is arranged behind the cooler and is also a measure for reducing the sticky bed. The whole process is carried out continuously, water quantity needs to be detected and adjusted continuously on line, workload is large, adjustment is inconvenient, and an intelligent self-adaptive management mode of an application system needs to be designed.

Disclosure of Invention

The invention aims to provide a water adding method of a sand cooler in a foundry plant and an intelligent water adding system matched with the method, which can change the physical state of used sand, which changes from the physical state of an inlet to the physical state of which an outlet tends to be constant, in the continuous treatment process and meet the requirements on the temperature and the humidity of the used sand.

The technical scheme of the invention is detailed as follows:

the invention provides a water adding method for a sand cooler of a foundry, which detects the humidity C1 and the temperature T1 of sand at the inlet of the sand cooler, detects the humidity C2 and the temperature T2 of the sand at the outlet of the sand cooler, calculates the water adding amount according to the detected humidity, temperature and sand throughput, and carries out distributed water adding, wherein the water adding amount calculation formula is as follows:

W＝We+Wm

wherein W is the total water addition; we is the amount of evaporated water, and the temperature compensation coefficient is multiplied by Ws from T1 to T2; wm is the amount of moisturizing water, and Wm is (C2-C1) multiplied by Ws; ws is the sand throughput; the temperature compensation coefficients for the inlet sand temperature T1 to the outlet sand temperature T2 are shown in the following table:

temperature compensation coefficient meter (%)

Note that: in the above table, the inlet sand temperature T1 is different, the outlet sand temperature T2 is 50 ℃, when the inlet sand temperature T1 is 130 ℃, the corresponding temperature compensation coefficient value of T1 to T2 is 5.5%, and when the inlet sand temperature T1 is 70 ℃, the corresponding temperature compensation coefficient value of T1 to T2 is 1.2%.

The research shows that the domestic cooler still adopts a mode of adding water according to the sand temperature, the stable outlet sand temperature of 50 ℃ and the water content of 2% can not be achieved basically, because the domestic cooler only controls 60-70% of the total water adding amount, the self water content of the used sand is unknown, particularly in the mixed line production, the mold is changed frequently, the sand-iron ratio is changed, the water content of the used sand is in a disordered state, and the remaining 30-40% of the water content can not be controlled, so that the manufacturers can only control the water content after cooling to be about 1.2-1.4% in order to avoid over-wetting.

The water adding method detects the temperature and humidity of the used sand entering the cooler, calculates the water adding amount according to the sand throughput, distributes water and sprays water in an atomizing mode, and therefore the problems can be solved. The reason is simple, the temperature of the sand is reduced by reducing the surface temperature and then reducing the internal temperature, the surface temperature reduction can be realized only by carrying away heat through surface water evaporation, and the evaporation efficiency is reduced on the contrary by adding excessive water instantly. In addition, enough ventilation of the cooler is ensured, evaporated moisture is discharged out of the cooler, and the moisture saturation of air in the cooler is kept to be reduced, so that the re-evaporation of the moisture can be effectively improved. According to the cooling performance of a conventional cooler, the water addition amount is calculated as (target water at an outlet-detected water after an inlet) x the sand throughput plus the evaporated water amount, and the evaporated water amount obtains empirical parameters according to years of practice, for example, the evaporated water amount is 3.0% of the sand throughput when the temperature of the sand at 100 ℃ is reduced to 50 ℃, and accounts for 60-70% of the total water addition amount. But the cooling efficiency of the coolers of each manufacturer is different, so this 3.0% is a variable. The actual result can be obtained through the detection of the sand temperature and the humidity of the sand outlet, the water adding amount is adjusted through the analysis of MES, and the ideal result of the sand temperature of 50 ℃ and the water content of 2% is finally obtained.

Through a lot of researches, the conclusion is that the water adding amount is critical, and the distribution mode of the added water is very important, because the high-temperature sand meets the water and evaporates in a continuous process, the water amount of the sand must be considered, the self heat of the sand and the evaporation capacity of the sand are considered, the heat of the sand is diffused from inside to outside, for example, stones burnt in a sauna room are poured with proper water, more hot steam is generated, and the furnace is extinguished after excessive water is poured. Therefore, in the designed water adding scheme, a distributed water adding mode is adopted, the water contact area of the sand is enlarged, the sand contacts water for multiple times in motion, the optimal distributed water spraying area reaches 50% of the area of the cooling bed, and the probability of contacting water is larger than 200%.

In order to obtain reliable detection data and accurately control the water adding process, the detection must be realized on line, real time and real. Moisture and temperature sensing may be accomplished on the belt. The capacitance method moisture measurement method is the most accurate and reliable method for measuring the moisture of the molding sand in the world at present.

Preferably, in the above water adding method, the distributed water adding is to arrange a multi-section nozzle in the sand passing area between the inlet and the outlet of the sand cooler, and the nozzle is selected to be a cone water arc. The spray water adding mode in the cooler adopts the conical water arc water adding mode, so that the bed sticking prevention, the over-wetting prevention and the uniform coverage area can be ensured.

Preferably, in the above water adding method, 4 rows of nozzles are arranged for the used sand passing through the region from high sand temperature to low sand temperature, and the water adding amount is distributed by: row 1 is 1.6 units, row 2 is 1.4 units, row 3 is 1 unit; the 4 th row is used for supplementing the water shortage;

defining the target humidity of the sand at the outlet of the sand cooler as Co, the target temperature as To, and the adjusting and controlling method of the water adding amount of the 4 rows of nozzles as follows:

(1) if C2 is Co, T2 is To, the water adding amount does not need To be adjusted, and the current water adding amount is continuously maintained; or

(2) If C2< Co, T2< To, increasing the water addition amount W1 of the 1 st To 3 rd rows, and W1 ═ Co-C2) xWs, evenly distributing the water addition amount To the 1 st To 3 th rows, and simultaneously increasing the water addition amount of the 4 th row until the state is adjusted To (1); or

(3) If C2< Co, T2> To, increasing the water adding amount W1 of the 1 st row To the 3 rd row, and evenly distributing W1 To (Co-C2) multiplied by Ws To 1 st row To 3 rd row water adding pipelines until the state is adjusted To (1); or

(4) If 2.2% > C2> Co and T2< To, the amount of water added in rows 1 To 3 is increased, W1 is (Co-C2). times.Ws, and the amount of water added in row 4 is decreased while equally distributing To the water adding lines in rows 1 To 3 until the state of (1) is adjusted.

Preferably, the water adding method also performs dust removal and ventilation operation in the water adding process. The dust removal and ventilation of the cooler not only controls the content (air permeability) of fine powder, but also has the cooling function of the cooler. More preferably, the humidity detection of the exhaust air can be provided, and the humidity detection is incorporated into an overall control system for logic control.

The invention also provides an intelligent water adding system for the sand cooler of the foundry, which comprises a detection system and a water adding system, wherein the water adding system comprises a main water supply pipe and 4 water supply branches, each branch comprises a barometer, an electromagnetic pneumatic angle valve, a water pipe arranged above a sand passing area in the sand cooler and a plurality of nozzles; the detection system comprises a sand humidity detection sensor and a temperature sensor which are arranged at an inlet of the sand cooler, and a sand humidity detection sensor and a temperature sensor which are arranged at an outlet of the sand cooler.

Preferably, in the above-mentioned intelligent water adding system, still include control system, control system includes PLC central control unit, and input unit and the display element who is connected with PLC central control unit respectively, and PLC central control unit still connects detecting system in order to collect the detection information, still connects the system of adding water in order to control and add water.

Preferably, in the above intelligent water adding system, the nozzles of the water adding system are sequentially distributed and arranged in rows 1 to 4 from top to bottom when the used sand passes through the region sand temperature, the water adding amount is 1.6 units in row 1, 1.4 units in row 2, and 1 unit in row 3; the 4 th row is used for supplementing the water shortage.

Defining that the target humidity of the sand at the outlet of the sand cooler is Co, the target temperature is To, and adjusting and controlling the water adding amount of the 4 rows of nozzles by the PLC central control unit in the following way:

Preferably, in the intelligent water adding system, the main water supply pipe is further provided with a pressure gauge, a filter and a flow meter.

Preferably, in the above-mentioned intelligent watering system, still include dust removal ventilation unit.

Compared with the prior art, the invention has the following beneficial effects:

the water adding method and the matched intelligent water adding system of the invention use sensor physical perception and intelligent control to form a self-adaptive system, so that the used sand is changed from a physical state with an inlet changing into a physical state with an outlet tending to be constant in the continuous treatment process, and the requirements on the temperature and the humidity of the used sand are met: the outlet sand temperature is less than 50 ℃, and the humidity is approximately equal to 2.0 percent.

Drawings

FIG. 1 is a schematic diagram of the overall structure of an intelligent water adding system for a sand cooler in a foundry;

FIG. 2 is a schematic diagram of the water addition zone distribution within the bubbling bed of a sand cooler;

FIG. 3 is a schematic view of the location of the temperature and humidity sensors of the sand cooler;

FIG. 4 is a side view of the water spray area of the water addition system spray head within the bubbling bed of the sand cooler;

FIG. 5 is a top view of the water spray area of the water addition system spray head within the bubbling bed of the sand cooler;

FIG. 6 is a schematic diagram of a display main interface;

FIG. 7 is a schematic view of an alarm interface;

FIG. 8 is a first (inlet parameter setting) schematic view of a parameter setting interface of the intelligent watering system;

FIG. 9 is a schematic view of a second parameter setting interface (first inlet temperature compensation setting) of the intelligent water adding system;

FIG. 10 is a schematic view of a second parameter setting interface (second inlet temperature compensation setting) of the intelligent water adding system;

FIG. 11 is a second schematic view of a parameter setting interface (outlet parameter setting) of the intelligent watering system;

FIG. 12 is a schematic view of a state interface of the intelligent watering system;

FIG. 13 is a schematic view of an analog interface of the intelligent watering system.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the corresponding technical solutions, the drawings that are needed in the embodiments or the prior art descriptions will be briefly described below.

Embodiment 1 Intelligent water adding system for sand cooler of foundry

Referring to fig. 1, the intelligent water adding system for the foundry sand cooler comprises a detection system, a water adding system, a control system and a dust removal air supply device. A self-adaptive system is formed by applying physical sensing and intelligent control of a sensor, so that the used sand is changed from a physical state with a changed inlet into a physical state with a constant outlet in the continuous treatment process, and the requirements on the temperature and the humidity of the used sand are met.

The water adding system comprises a main water supply pipe and 4 water supply branches, and a pressure gauge, a filter and a flowmeter are arranged on the main water supply pipe. Each of the 4 water supply branches includes a barometer, an electromagnetic pneumatic angle valve, a water pipe arranged above a sand passing region (i.e., a bubbling bed of the sand cooler) in the sand cooler, and a plurality of nozzles. The nozzles are distributed and arranged into the 1 st row to the 4 th row according to the sand temperature from high to low in sequence to form 4 rows of water injection zones, the installation interval is determined according to the passing speed of sand in the fluidized bed, the characteristic of full high evaporation water content after the water is added into the first 3 rows is ensured, and the water stopping interval is reduced as much as possible. For example, 2 water addition zones can be defined: the evaporation zone and the humidification zone, the division of the 4 rows of nozzles: 1-3 rows are arranged in an evaporation zone to add water to compensate the evaporation water amount, and the 4 th row is arranged in a humidification zone to be responsible for humidifying and adding water, which is shown in figure 2. The quantity of the nozzles is determined according to the theoretical calculation of the sand capacity of the cooler, the capacity of the general sand cooler is 40-220 tons/hour, the quantity of the nozzles is 4-40, the nozzles select water spraying to be conical water arcs, the water adding quantity is 0.1-0.5 liter/second, the installation quantity, angles and heights are designed according to the structure and the capacity of the cooler, and the uniform water adding thickness and the highest coverage rate are ensured. The water pressure of the water adding quantitative system is greater than 2.5Mpa, the dust removal air supply device utilizes a blower to form wind power and sends the wind power into the sand cooler, the pressure of compressed air is greater than 4.5Mpa, the flow meter is in an impulse type, the stop valve adopts a pneumatic angle valve, and the quantitative water adding precision is less than 0.1%. The system is provided with water pressure/air pressure detection and over-low alarm functions.

The detection system comprises a sand humidity detection sensor and a temperature sensor which are arranged at the inlet of the sand cooler, and a sand humidity detection sensor and a temperature sensor which are arranged at the outlet of the sand cooler.

The humidity detection sensor adopts a wedge-shaped moisture measurement sensor based on a traditional capacitance method, and is used for measuring the humidity of sand during the operation of a belt, 2 capacitance electrodes are arranged in the humidity measurement sensor, a probe of the humidity sensor is embedded in the moving used sand by the used sand on the belt during the operation of the belt, the sand is in contact with the sensor, the used sand is a medium capacitor, the moisture change of the used sand causes the capacitance change, the humidity value is calculated through linearization processing, and the moisture of the sand between 2 electrodes is measured. The detection precision of the sand humidity is < - +/-0.2 percent.

The temperature sensor is also of the contact type, the probe sensing part of which is inserted in the sand of the belt and the temperature is measured by the resistance method. The detection precision of the temperature sensor is < +/-2 ℃.

The temperature sensor and the humidity sensor are matched and simultaneously installed.

The positions of detection are typically installed in 2 positions: on the belt at the inlet and outlet of the cooler. The detection at the inlet provides data for judging the water adding amount for humidification and cooling, and the detection at the outlet detects the humidification and cooling result.

The sensor is the basic assurance of system intellectuality and digitization, and sand cooling is continuous type operation, and the ability is big to 200 tons per hour, in case the unattended operation, can't guarantee subsequent molding sand quality.

The control system comprises a PLC central control unit, an input unit and a display unit which are respectively electrically connected with the PLC central control unit, and the PLC central control unit is also connected with a detection system to collect detection information and is also connected with a component needing to be controlled in the water adding system to control water adding.

The control system takes outlet detection value as reality, sets a target as virtual, establishes a digital twin system, takes each second as a polling period, establishes a self-adaptive logic system, and can realize automatic deviation correction and alarm.

The display unit of the control system is a 5.7-inch touch liquid crystal display, and the following contents are displayed:

cooler measurements and operating parameters are displayed on a 5.7 inch touch liquid crystal display for each cooler;

controlling the target of a cooler, wherein the water content is 0-2.0%, and the fine temperature is controlled to +/-0.2%;

dynamic monitoring, and real-time display of technological parameters;

displaying and alarming system faults;

alarming when the water content is over-wet;

water and air pressure loss alarm;

panel and pilot lamp.

Main interface of display referring to FIG. 6, the main interface is illustrated as follows:

1. the sand flow and humidity set values can be directly modified, and when the water content detected in a laboratory is higher than the set values, the set values are reduced; the phase reaction increases the set point. When the laboratory detection value is greater than or less than the set value of 0.2%, the humidity parameters A0 and A1 are adjusted. When the laboratory values are equal errors from the setpoint, their difference is added to AO when the laboratory values are greater than the setpoint, and conversely, their difference (which is a negative value) is added to AO. When the laboratory value and the set value are not equal in error, and when the used sand humidity is changed from small to large, the A1 (more than 1 adjustment) is adjusted when the error between the laboratory value and the set value is large; instead, a1 should be adjusted to less than 1.

2. And displaying the humidity and the temperature of the inlet and the outlet in real time.

3. And dynamically displaying the water adding amount of each group of valves.

4. Signal description of indicator lights:

moisture measurement signal: the cooler has activated the emitted signal.

Allow water addition signal: the cooler is started and operated for a period of time and a signal is given when it is confirmed that the cooler is full of sand (both signals may be sent out simultaneously).

Alarm signal: the cooler sends out an under-voltage alarm and an excessive water adding state.

The function keys of the main interface are explained as follows:

setting parameters: and skipping to a parameter setting interface, wherein the login is effective after success.

Analog quantity: and jumping to a system analog quantity display interface.

The system state is as follows: jump to the system state interface.

And (3) alarm information: jump to the alarm message interface.

Closed-loop control: closed loop control is to press the button to be on in a 'stop' state; in the "on" state, the button presses "off".

The alarm interface is shown in fig. 7. The alarm interface is illustrated as follows:

the interface may be called up by pressing an alarm message button of the main interface. The alarm messages are contained in 3 types:

insufficient water pressure: indicating that the water pressure is too low;

insufficient air pressure: indicating that the air pressure is too low;

over-wetting means that it occurs when the amount of added water is greater than the maximum amount of added water.

Function key description of alarm interface:

and returning: jump to the home interface.

The intelligent water adding system parameter setting interface I (see FIG. 8) is described as follows:

valve 1 flow (liters/sec): flow rate at which the first set of valves are open.

Valve 2 flow (liters/sec): the second set of flow rates at which the valve is open.

Valve 3 flow (liters/sec): the third set of flow rates at which the valve is open.

Valve 4 flow (liters/sec): the fourth set of flow rates at which the valve is open.

And after the water adding signal is confirmed, the water adding is started after time delay.

Humidity parameter a 0: the amount of humidity offset.

Humidity parameter a 1: the humidity was divided.

Temperature parameter a 0: the amount of temperature offset.

Temperature parameter a 1: the temperature was divided.

Water addition period (S). And setting cycle time, determining the sand amount in the cycle time, and calculating the water adding amount.

The description of each function key of the parameter setting interface of the intelligent water adding system is as follows:

temperature compensation parameters: jumping to a temperature compensation interface;

and (3) outlet parameters: jumping to an exit parameter interface;

and (3) confirmation: jump to host interface from PLC to write data

And returning: jump to the home interface.

And a second intelligent water adding system parameter setting interface (see fig. 9-11), which is described as follows:

the password login method is used for login of an administrator, and when the password is correctly logged in successfully, parameter setting can be performed. The temperature compensation refers to the humidity evaporation capacity of the used sand in the conveying process, and the arrangement is determined by field workers according to actual conditions.

The function keys are explained as follows:

entrance parameters: jumping to an entrance parameter interface;

and (3) confirmation: jump to host interface from PLC to write data

And returning: jump to the home interface.

And (4) upper page: jumping to a parameter interface set by the cooler inlet temperature compensation;

and (4) page: jump to the cooler inlet temperature compensation setting two parameter interface.

The system state interface of the intelligent water adding system is shown in fig. 12, and the interface illustrates that: and the state of each input/output point of the intelligent water adding system is displayed, and whether each signal return is correct or not can be detected when the system is overhauled. Description of function keys: and returning: jump to the home interface.

The analog interface is shown in fig. 13, and the interface illustrates:

displaying information: and the temperature sensor and the humidity sensor are used for displaying the corresponding voltage value in real time after the signals of the humidity sensor are processed by the operation unit.

The humidity display represents a (uncorrected) humidity value corresponding to 5-10. The temperature is 0 to 10 and is 0 to 100 ℃ correspondingly.

Description of function keys:

and returning: jump to the home interface.

Example 2 Water addition method

The temperature reduction is realized by evaporating surface water by the heat of the sand and pumping steam with supersaturated humidity by a ventilation system, so that a large amount of added water is evaporated, and part of water is remained in the sand for humidification, so that the total added water amount W is the evaporated water amount We + the humidified water amount Wm. The water evaporation amount is different according to the requirements of the sand outlet temperature, for example, the sand temperature at the outlet reaches 50 ℃, the water evaporation amount (namely the temperature compensation coefficient) is 0.7 percent of the weight of the sand when the sand temperature at the inlet is 60 ℃, and the water evaporation amount is 4.5 percent of the weight of the sand when the sand temperature at the inlet is 120 ℃. The evaporation amount of water at different temperatures is an empirical value summarized in years, and particularly refers to a temperature compensation coefficient table.

The residence time of the sand in the cooler during the continuous cooling process was calculated as 60 seconds and we read the measurement data every 1 second, e.g. the cooler throughput per second was 27kg (Ws) with a capacity of 100 tons/h. The cooler inlet detection data (C1, T1) and the target data (Co, To) of the outlet sand and the calculated water addition amount (W1) are regarded as a pair of twin data, and the sand outlet detection data (C2, T2) and the actual water addition amount (W1) are regarded as a pair of twin data.

Temperature compensation coefficient meter (%)

When the inlet sand temperature is 120 ℃ and the outlet temperature is required to be reduced to 50 ℃, the inlet sand humidity is 0.1 percent and the outlet sand humidity is 2 percent, and the water adding amount per second is as follows:

the temperature compensation coefficient × Ws of We ═ T1 to T2 ═ 4.5% × 27kg/s ═ 1.215L/s.

Wm＝(C2-C1)×Ws＝(2％-0.1％)×27kg/s＝0.513L/s

W＝We+Wm＝1.728L/s。

The shower nozzle of intelligence water system arranges and defines 2 water areas of adding: the evaporation zone and the humidification zone, the division of the 4 rows of nozzles: 1-3 rows are arranged in an evaporation zone to add water to compensate the evaporation water amount, and the 4 th row is arranged in a humidification zone to be responsible for humidification and water addition.

The sand temperature is from high to low from the 1 st row to the 3 rd row, the speed of the evaporated water quantity is from high to low, and the water quantity is added to the 3 rd row and is 1 unit; row 2 is 1.4 units; row 1 is 1.6 units. The number of nozzles and the time for opening and closing the valve per passage are selected based on this.

There are 4 conditions that occur according to the exit detection:

(1) if C2 is Co, T2 is To, the water adding amount does not need To be adjusted, and the current water adding amount is continuously maintained;

(2) if C2< Co, T2< To, increasing the water addition amount W1 of the 1 st To 3 rd rows, and W1 ═ Co-C2) xWs, evenly distributing the water addition amount To the 1 st To 3 th rows, and simultaneously increasing the water addition amount of the 4 th row until the state is adjusted To (1);

(3) if C2< Co, T2> To, increasing the water adding amount W1 of the 1 st row To the 3 rd row, and evenly distributing W1 To (Co-C2) multiplied by Ws To 1 st row To 3 rd row water adding pipelines until the state is adjusted To (1);

Will import and export temperature, humidity detection, export temperature, humidity set target, add water yield data and establish the database to set up temperature and humidity trend curve and alarm line, humidity is reported to the police: 1-over-wet (set 2.2%), 2-over-dry (set 1.2%), temperature alarm: 1) too high (set 60 ℃), set shift/day/month trend display.

And calculating the water adding time of each group to control the water adding amount through the initially set flow of each group of water adding valves of the flow meter.

The temperature is significant for measuring the moisture and calculating the evaporation capacity of the added water. The temperature value is the cooling water adding amount by multiplying the evaporation coefficient by the sand amount, and is also the evaporation water amount; the difference between the humidity value and the molding sand set value is multiplied by the weight of the used sand equal to the humidifying water addition amount in the set time period, 2 water addition amounts are combined into the total water addition amount, and the total water addition amount is added into the cooler through the water adding nozzle according to the set time and the set amount. The cooler type sand moisture control system is provided with two groups of probes, wherein the two groups of probes are respectively arranged at the inlet and the outlet of the cooler, the temperature and humidity probes at the inlet detect the temperature and the humidity of the old sand and control the water adding amount according to target values, and the temperature and humidity probes at the outlet detect the difference between the temperature and the humidity of the old sand and the target values and can feed the difference back to a PLC central control unit to form closed-loop control.

The used sand is humidified and cooled by physical sensing detection of a water adding system and control of an intelligent self-adaptive system, the temperature of sand at the outlet of a cooler is less than 50 ℃, and the humidity is approximately equal to 2.0%.

The casting world in China pays more and more attention to potential increase and temperature reduction, a sand treatment system with the capacity of more than 60 tons basically needs to be added with a humidification and temperature reduction function, all industrial manufacturing is converted into intellectualization and digitalization at present, and the intelligent water adding system and the water adding method have huge markets.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A water adding method for a sand cooler of a foundry is characterized in that the humidity C1 and the temperature T1 of sand are detected at the inlet of the sand cooler, the humidity C2 and the temperature T2 of the sand are detected at the outlet of the sand cooler, the water adding amount is calculated according to the detected humidity, temperature and sand throughput, and distributed water adding is carried out, wherein the water adding amount calculation formula is as follows:

W＝We+Wm

wherein W is the total water addition; we is the amount of evaporated water, and the temperature compensation coefficient is multiplied by Ws from T1 to T2; wm is the amount of moisturizing water, and Wm is (C2-C1) multiplied by Ws; ws is the sand throughput; the temperature compensation coefficients for inlet sand temperature T1 to outlet sand T2 are shown in the following table:

temperature compensation coefficient meter (%)

2. The method of adding water of claim 1 wherein the distributed addition of water is by providing a multi-segment nozzle in the sand-passing region between the inlet and outlet of the sand cooler, the nozzle being shaped as a cone-shaped water arc.

3. The water adding method according to claim 2, characterized in that 4 rows of nozzles are arranged from high sand temperature to low sand temperature in the used sand passing region, and the water adding amount is distributed in a mode that: row 1 is 1.6 units, row 2 is 1.4 units, row 3 is 1 unit; the 4 th row is used for supplementing the water shortage;

4. The method for adding water according to claim 1, wherein a dedusting and ventilating operation is further performed during the water adding process.

5. An intelligent water adding system for a sand cooler in a foundry, which comprises a detection system and a water adding system and is characterized in that,

the water adding system comprises a main water supply pipe and 4 water supply branches, wherein each branch comprises a barometer, an electromagnetic pneumatic angle valve, a water pipe arranged above a sand passing area in the sand cooler and a plurality of nozzles;

the detection system comprises a sand humidity detection sensor and a temperature sensor which are arranged at an inlet of the sand cooler, and a sand humidity detection sensor and a temperature sensor which are arranged at an outlet of the sand cooler.

6. The intelligent water adding system according to claim 5, further comprising a control system, wherein the control system comprises a PLC central control unit, and an input unit and a display unit which are respectively connected with the PLC central control unit, the PLC central control unit is further connected with a detection system to collect detection information, and is further connected with a water adding system to control water adding.

7. The intelligent water adding system according to claim 6, wherein nozzles of the water adding system are distributed and arranged in rows 1-4 from high to low in the sand temperature in the used sand passing area, the water adding amount is 1.6 units in row 1, 1.4 units in row 2 and 1 unit in row 3; the 4 th row is used for supplementing the water shortage;

8. The intelligent water adding system according to claim 5, wherein the main water supply pipe is further provided with a pressure gauge, a filter and a flow meter.

9. The intelligent watering system of claim 5, further comprising a dust removal ventilation device.