CN116735414A - Automatic testing device and method for mud content of raw sand for casting - Google Patents

Abstract

The invention discloses an automatic testing device and method for the mud content of raw sand for casting, which belong to the field of raw sand measurement for casting. According to the method, dynamic separation of raw sand and mud in a sand washing cup is realized through a stirring device and a filtering device, the turbidity of mixed liquid in the sand washing cup is collected in real time by adopting a turbidity sensor in the dynamic separation process, the mud content of the raw sand is automatically calculated by utilizing a mathematical model between the turbidity of the mixed liquid and the mud content of the raw sand, and a mud content test value is displayed on a panel. The method realizes the integrated design of vortex washing, separation of raw sand and mud, and measurement, can automatically judge the sand washing end point according to the turbidity of turbid liquid, solves the problems of more or fixed times and overlong time of the original automatic sand washing process, avoids the processes of repeated water adding siphon, drying and weighing, saves the cost of equipment required by drying and weighing, can finish the testing of mud content in the sand washing process, and greatly shortens the testing process and time.

Description

Automatic testing device and method for mud content of raw sand for casting

Technical Field

The invention relates to the field of measurement of the mud content of raw sand in casting, in particular to an automatic testing device and method for the mud content of raw sand for casting.

Background

The raw sand is an important component of wet clay sand, and is referred to as aggregate of molding sand. Therefore, it is necessary to control the quality of the molding sand, wherein the mud content of the raw sand is an important index of the raw sand, and the mud content of the raw sand directly affects the properties of the molding sand, and has a great influence on the strength, air permeability, refractoriness and the like of the molding sand. The mud fraction contained in the raw sand often has a considerable part other than the clay mineral composition, and the binding property is inferior to that of ordinary clay. Therefore, the mud content of the raw sand must be controlled in production, and the method has important significance for detecting and controlling the mud content of the raw sand.

At present, the determination of the mud content of the raw sand mainly adopts a differential value method specified in GB/T2648-2009, and the principle is mainly that the mud is above a siphon orifice according to the sedimentation rule of solid particles in water. According to the method, liquid at the upper part of a siphon pipe orifice is completely siphoned out by using a siphon pipe, then water is added, stirring, standing and siphoning are carried out repeatedly until the water is clear, so that mud separated after vortex washing can be completely discharged, and then the weight difference of front and rear raw sand accounting for the total mass of the raw sand is calculated through filtering, drying and weighing, so that the mud content is calculated. The method has the advantages of multiple steps, large amount of ginseng, long time consumption, and inconvenient measurement. Therefore, in order to simplify the problems of complicated measurement, long time consumption and the like, the device and the method for automatically testing the mud content of the raw sand for casting are provided.

Disclosure of Invention

The invention aims to solve the problems of troublesome process, long time consumption, large manual workload and the like in the conventional process for detecting the mud content of raw sand, and provides an automatic testing device and method for the mud content of the raw sand for casting.

An automatic testing device for the mud content of raw sand for casting mainly comprises a speed-adjustable motor (1), a stirring head (2), a light shield (3), a filter screen (4), a cylinder body (5), an operating table (6), a sensor (7), a lifting table (8) and a bracket (9); the filter screen (4) and the cylinder body (5) are positioned on the same central axis to form a water sump, the light shield (3) plays a role in shading light, and the liftable motor (1) is connected with the stirring head (2) and positioned right above the cylinder body; the motor is connected with a bracket (9) and can adjust the height of the motor, and a turbidity acquisition device is formed by a sensor (7) and a lifting table (8); is fixed in the cylinder body, and the operating platform (6) is positioned right below the cylinder body.

The automatic testing device for the raw sand content for casting realizes the operation of rapidly testing the raw sand content, and comprises the following steps:

s1, lifting a sensor to a proper position;

s2, opening a light shield, checking whether foreign matters exist in the filter screen, weighing 50g of sample raw sand, and uniformly placing the sample raw sand in the filter screen; adding 800ml of water into the cylinder, covering a light shield, checking the light shielding property, and performing the next step without error;

s3, adjusting the rotating speed of the motor to 4000 revolutions per minute by using an operation table key, and adjusting the motor to a correct position; then, using a key to control the start of washing, and driving the raw sand in the filter screen by the motor to continuously separate the raw sand from the mud;

s4, initializing chips or devices such as STC89C52 single-chip microcomputer, LCD display and buzzer; the sensor is controlled to work, the singlechip controls the sensor to read data, the data is converted through the A/D module, and when the sensor reads that the value of the raw sand turbid liquid to be measured is stable, the mathematical model is utilized to calculate and obtain the raw sand mud content;

an automatic testing device for the mud content of raw sand for casting comprises the following specific method and steps of turbidity treatment:

s31, preparing raw sand with different mud contents by using cleaning sand, and weighing by an electronic balance: the mud content is 50g of each of the raw sand with the respective content of 1%, 0.8%, 0.6%, 0.4% and 0.2%; five groups of raw sand with different mud contents are taken for experiments respectively;

s32, respectively placing the configured raw sand to be tested with different mud contents into a sand washing device shown in a figure 1, starting sand washing until the readings of the sensor are stable, respectively reading the turbidity, and recording experimental data;

s33, processing each group of data and converting the data into characteristic values;

s34, constructing a mathematical model between the mud content and the characteristic value;

compared with the prior art, the invention has the advantages and accumulation effects that:

the invention aims to start from the turbidity difference and the particle size of the raw sand with different mud contents. Based on the principle that the national standard method separates mud from raw sand, the raw sand and the mud can be dynamically separated while washing the sand, then turbidity is measured by a sensor to be converted into mud content, and the sand washing end point is automatically judged after the reading of the sensor is stable, so that the problems of large manual participation, long consumption time, complicated measuring process, inaccurate measuring result and sedimentation waiting during the measuring of the sensor in the existing raw sand mud content measuring method are solved, the repeated sand washing and siphoning processes are omitted, and the measuring result is reduced from several hours to more than ten minutes, thereby realizing the rapid measuring of the raw sand.

Drawings

FIG. 1 is a schematic diagram of a device for automatically testing the mud content of raw sand for casting.

FIG. 2 is a flow chart of a new method of measuring the mud content of raw sand.

Detailed Description

The first embodiment is as follows:

the method of use of the invention is further described below in conjunction with fig. 2:

s1, lifting a sensor to a proper position through a device shown in the figure 1;

s2, opening a light shield, checking whether foreign matters exist in the filter screen, weighing 50g of sample raw sand, and uniformly placing the sample raw sand in the filter screen; adding 800ml of water into the cylinder, covering a light shield, checking the light shielding property, and performing the next step without error;

s3, adjusting the rotating speed of the motor to 4000 revolutions per minute by using an operation table key, and adjusting the motor to a correct position; and then, using a key to control washing to start, stopping washing sand after the reading of the sensor is stable, returning the characteristic value to the program, and directly displaying the mud content of the raw sand through an LCD.

The second embodiment is as follows:

the establishment of the mathematical model is further elucidated with reference to fig. 2:

s31, measuring the raw sand through a detection device as shown in figure 1, and performing test measurement on five groups of raw sand with different mud contents (the mud contents are 1%, 0.8%, 0.6%, 0.4% and 02% respectively);

s32, washing sand for each group of experiments until the reading of the sensor is stable, preprocessing the obtained experimental data, and averaging the data of each mud content to obtain a characteristic value;

s33, comparing and drawing the obtained characteristic value and the true value into a table, and fitting the table into a mathematical relation by MATLAB;

s34, calculating the mud content of the raw sand sample according to the pre-constructed mathematical relation model of the mud content.

Claims (5)

1. An automatic testing device and method for the mud content of raw sand for casting are characterized in that: the device comprises a speed-adjustable motor (1), a stirring head (2), a light shield (3), a filter screen (4), a cylinder body (5), an operating table (6), a sensor (7), a lifting table (8) and a bracket (9); the filter screen (4) and the cylinder body (5) are positioned on the same central axis to form a water sump, the light shield (3) plays a role in shading light, and the liftable motor (1) is connected with the stirring head (2) and positioned right above the cylinder body; the motor is connected with the bracket (9) and can adjust the height of the motor up and down, and the sensor (7) and the lifting table (8) form a turbidity acquisition device; is fixed in the cylinder body, and the operating platform (6) is positioned right below the cylinder body.

2. The automatic testing device for the mud content of the raw sand for casting according to claim 1, which is characterized in that a motor (1) and a stirring head (2) clean the raw sand in a filter screen (4) to drive turbid liquid to flow out of the filter screen (4), wherein the filter screen (4) is made of stainless steel, and the pores with 800 meshes are selected to be smaller than 20 mu m; the method can separate mud during sand washing, raw sand turbid liquid is arranged in the filter screen, mud turbid liquid is arranged outside the filter screen, turbidity of the turbid liquid outside the filter screen is collected in real time, and the turbidity characterization range is 0-5v.

3. The automatic testing device for the mud content of the raw sand for casting according to claim 1, wherein in the cleaning process of the raw sand, the turbidity sensor is used for dynamically detecting the turbidity of the mixed liquor in real time to automatically judge the sand washing end point, and the mud content is automatically calculated according to a mathematical model of the mud content of the raw sand and the turbidity of the mixed liquor, so that the processes of washing sand, filtering, drying and weighing for a plurality of times are not needed.

4. An automatic testing device for the mud content of raw sand for casting, which is operated based on the testing device of claim 1 and comprises the following steps:

s1, lifting a sensor to a proper position;

s2, opening a light shield, checking whether foreign matters exist in the filter screen, weighing 50g of sample raw sand, and uniformly placing the sample raw sand in the filter screen; adding 800ml of water into the cylinder, covering a light shield and checking the light shielding property;

s3, adjusting the rotating speed of the motor to 4000 revolutions per minute by using an operation table key, and adjusting the motor to a correct position; then, using a key to control the start of washing, and driving the raw sand in the filter screen by the motor, wherein the raw sand and the mud are continuously separated in stirring;

s4, initializing chips or devices such as STC89C52 single-chip microcomputer, LCD display and buzzer; the sensor is controlled to work, the singlechip controls the sensor to read data, the data is converted through the A/D module, and sand washing is stopped when the sensor reads that the value of the raw sand turbid liquid to be detected is stable; and meanwhile, calculating the mud content of the raw sand by using the established mathematical model between the turbidity of the mixed liquor and the mud content of the raw sand.

5. The method for testing the mud content of the raw sand, which is based on the mathematical model establishment between the turbidity of the mixed liquor and the mud content of the raw sand, comprises the following specific steps:

s31, preparing raw sand with different mud contents by using cleaning sand, and weighing by an electronic balance: 50g of raw sand with the mud content of 1%, 0.8%, 0.6%, 0.4% and 0.2% respectively; five groups of raw sand with different mud contents are taken for experiments respectively;

s32, respectively placing the configured raw sand to be tested with different mud contents into a sand washing device shown in the figure 1, washing the sand until the sensor reading characteristic value is stable, respectively reading the turbidity, and recording experimental data;

s33, processing each group of data and converting the data into characteristic values;

s34, constructing a mathematical model between the mud content and the characteristic value.