CN109902364B - Method for improving uniformity of spray-grouting felt making - Google Patents

Abstract

The invention belongs to the technical field of heat preservation felt production, and particularly relates to a method for improving uniformity of guniting felt making, which comprises the following steps: step 1, obtaining a relation equation of radius and thickness distribution in concentric circle plaque sprayed by actual slurry; step 2, generating a filter screen interface; step 3, generating a simulated concentric circular plaque on the filter screen interface according to the relation equation in the step 1; step 4, the concentric circles of plaques move on the filter screen interface according to a set movement rule; step 5, after the movement is completed, counting the accumulated thickness of the felt formed on the filter screen interface, and evaluating the thickness distribution uniformity of the felt; step 6, changing the setting parameters of the movement rule in the step 4, and repeating the steps 4 and 5 to obtain the movement rule of the atomizer for manufacturing the felt with good uniformity; the invention realizes the organic superposition and mutual compensation of multilayer spraying, obtains the felt body with good uniformity, and guides the production of the felt body.

Description

A Method of Improving the Uniformity of Shotcrete Felting

technical field

The invention belongs to the technical field of thermal insulation felt production, and in particular relates to a method for improving the uniformity of spraying felting.

Background technique

As a common thermal insulation equipment, thermal insulation felt has been favored by more and more factories and enterprises due to its good thermal insulation performance and wide application fields. Insulation felt has the characteristics of light material, good heat preservation effect, simple and convenient construction, reusable, small production investment and quick effect. It can reduce a lot of energy consumption in the actual use process, so the development prospect is very broad. Today, global thermal insulation materials are developing towards the direction of high efficiency, energy saving, thin layer, thermal insulation, waterproof and external protection integration. While developing new thermal insulation materials and conforming to structural thermal insulation and energy-saving technologies, more emphasis is placed on the targeted use of thermal insulation Thermal insulation materials are designed and constructed according to standard specifications, and efforts are made to improve thermal insulation efficiency and reduce costs. Insulation felt is made of fiber slurry, and the production process mainly includes pulping, spray molding, drying and other processes. Among them, spray molding is one of the key factors to ensure the quality of thermal insulation felt. The main goal of spray molding is to spray the fiber slurry evenly on the filter membrane to ensure the uniformity of the thermal insulation felt.

The current spray atomization nozzle usually adopts the pressure atomization technology, that is, the slurry enters the atomizer under the pressure and atomizes. Since the droplet flow field sprayed by the atomization nozzle is a conical flow field, the flow field is The serous plaque formed by the plane filter membrane is a circular plane. Due to the non-uniformity of spraying slurry by the atomizer, usually the plane is a concentric circle with non-uniform thickness. The production process of thermal insulation felt is formed by multiple spraying and covering. Under the premise of multi-layer covering, how to control the covering mechanism according to the unevenness of concentric circles, that is, adjust the displacement law of the nozzle in the x and y directions, so that Realizing the organic superposition and mutual compensation of multiple layers, so as to realize the uniformity of the insulation blanket, is the key technology of the insulation blanket production. Since the covering process involves complex factors such as the thickness distribution of concentric circles and the moving rate in the x and y directions, how to find the best moving law to meet the uniformity requirements of the felt body is currently a difficult point.

Contents of the invention

The invention solves the above-mentioned technical problems existing in the prior art, and provides a method for improving the uniformity of spray felting.

In order to solve the above problems, the technical solution of the present invention is as follows:

A method for improving the uniformity of spray felting, comprising the following steps:

Step 1, obtain the relational equation of the radius and thickness distribution in the concentric circular patch of actual slurry spraying;

Step 2, generate the filter screen interface;

Step 3, according to the relationship equation described in step 1, generate simulated concentric circle plaques on the screen interface;

Step 4, the concentric plaques move on the screen interface according to the set moving rule;

Step 5, after the movement is completed, count the cumulative thickness of the felt body formed on the filter screen interface, and evaluate the uniformity of the thickness distribution of the felt body;

In step 6, change the setting parameters of the movement law in step 4, and repeat steps 4 and 5 to obtain the movement law of the atomizer for making felt bodies with uniform thickness distribution.

Preferably, the relational equation described in step 1 is obtained by fitting the actual distribution of radius and thickness in the concentric plaques.

Preferably, the fitting method described in step 1 is: spray the slurry onto the flat filter screen at a fixed position by the atomizer to obtain concentric circular patches of the slurry, measure the average thickness of the circular spots at different radii, and obtain the radius of the circular spots and the slurry The data of thickness distribution is used to fit the relationship equation between the radius and thickness distribution in the heart circle plaque.

Preferably, in the step 2, the filter screen interface performs grid division, and the coordinates of each grid are marked and numbered.

Preferably, in the step 3, the position coordinates of the initial spraying are set on the filter screen interface, and the distance between each grid on the filter screen interface and the initial spraying position is calculated, and the network within the range of the simulated concentric circle patch Add a digital mark to the grid, and the digital mark represents the thickness of the concentric circular spot at the grid position.

Preferably, in the step 4, the setting parameters of the movement rule include speed movement and movement trajectory.

Preferably, in step 4, a digital mark is added to the grid covered by the simulated concentric circles moving; when the concentric circles cover the same grid at different times, the digital marks on the grid are accumulated.

Preferably, in the step 5, after the movement is completed, the digital mark values in each grid of the filter screen are counted, and converted into the thickness distribution of the felt body on the filter screen.

Preferably, in said step 5, evaluating the uniformity of the felt body thickness distribution is by measuring the variance of the uniformity of the felt body thickness distribution, thereby obtaining the uniformity of the felt body made under the movement rule; generally, for a felt body with an average thickness of 1cm The felt body is regarded as a uniform felt body when the uniformity variance is less than 0.05.

Compared with the prior art, the advantages of the present invention are as follows,

The present invention utilizes the numerical simulation method, according to the thickness distribution equation of the atomizer to spray the concentric circular spot, by controlling the coverage mechanism, adjusts the displacement law of the spray head, realizes the organic superposition and mutual compensation of multi-layer spraying, and obtains a felt body with good uniformity, Guide the production of felt body;

In the method for improving the uniformity of sprayed felting provided by the present invention, the theoretical simulation data and the felt body uniformity data obtained by the actual sprayed felting method have been compared and verified, and the relative error is within 6%. The actual production operation of felt provides the basis.

Description of drawings

Fig. 1 is the concentric circular spot thickness distribution relation obtained by providing the atomizer to spray the slurry, and the simulated circular spot is generated on the meshed filter screen;

Fig. 2 is the situation of felt body formation when the circular spot moves;

Figure 3 shows the felt body with good uniformity obtained by changing the movement law.

Detailed ways

Example 1:

Provide the relationship equation between the radius and thickness distribution in the concentric circle spot obtained by spraying the slurry from the atomizer, write the program of the method and complete the parameter setting, and then simulate the atomizer moving at a certain speed to make the thickness distribution curve of the felt body, and measure the felt body body uniformity. The specific route is:

(1) Measure the relational expression of the thickness and radius distribution of the concentric circles of the sprayed slurry on the filter membrane for the used spray nozzle;

(2) Divide the filter surface into grids according to the required felting size, and mark and number the coordinates of each grid;

(3) Set the coordinates of the initial spraying position on the filter, measure and calculate the distance between each grid of the filter screen and the initial spraying position, and add Number mark, the number mark represents the thickness of the concentric circular spot on the grid position;

(4) Concentric circular spots move at a set speed, representing the movement of the atomizer during spraying, and adding digital marks to the grid covered during movement. When the concentric circles cover the same grid at different times, the digital marks on the grid are accumulated;

(5) After the movement is completed, the digital mark value in each grid of the filter screen is counted, which can be converted into the thickness distribution of the felt body on the filter screen;

(6) and calculate the variance of the uniformity of the thickness distribution of the felt body. Thus, the uniformity of the felt body produced under this moving rule can be obtained; generally, for a felt body with an average thickness of 1 cm, when the uniformity variance is less than 0.05, it is regarded as a uniform felt body.

(7) Through continuous felting simulation tests, the movement law of the atomizer for making felts with good uniformity can be obtained.

Example 2:

Step 1: Select a pressure swirl atomizer with an atomization angle of 30 degrees, and spray it at a height of 30 cm from the filter to obtain concentric circular plaques of the slurry, and measure the average thickness of the circular plaques at different radii to obtain circular plaques According to the data of the radius and thickness distribution of the slurry, the relationship equation of the radius and thickness distribution in the heart circle patch is fitted by this data: h=4E-05r ⁴ -0.0021r ³ +0.022r ² +0.007r+0.4456, the circle spot The radius is 18 cm and the equation fit is 0.9967.

Step 2: Write a program according to this method. Input the circle spot radius and thickness distribution equation obtained in step 1, and the circle spot radius information into the program, and set the initial size of the filter screen, with a length of 5000mm and a width of 5000mm; the calculation step is 0.1s, and the total calculation time is until the felt is fully covered The filter frame shall prevail; the initial position coordinates of the nozzle on the x-axis and y-axis are both (600,600). Each felting simulation is uniformly produced with an average thickness of 1cm thick felt body.

Step 3: Test the influence of the moving speed of the atomizer in the x direction on the uniformity of the felt body. When the moving speed of the atomizer in the x direction is 0.12m/s, the variance of the uniformity of the felt body is 0.171245. When the moving speed is reduced from 0.12m/s to 0.06m/s, the uniformity of the felt body is greatly improved. Every time the speed of the atomizer is reduced by 0.01m/s, the uniformity variance of the felt body can be reduced by 0.02624; The uniformity variance of the felt body can be reduced by 0.00273. When the moving speed is 0.07m/s, the uniformity variance of the felt body is up to 0.04418, which meets the uniformity requirement of the felt body.

Step 4: Test the influence of the moving distance of the atomizer in the y direction on the uniformity of the felt body. When the moving distance in the y direction of the atomization is 1r (that is, double the radius length), the variance of the uniformity of the felt body is 0.38582. When the moving distance in the y direction is reduced from 1r to 0.6r, the average moving distance of 0.1r is reduced, and the felt body The uniformity variance can be reduced by 0.06273; when the moving distance of the atomizer in the y direction is less than 0.06m/s, the uniformity variance of the felt body can be reduced by 0.01024 for every reduction of the moving distance of the atomizer by 0.1r. When the moving distance of the atomizer in the y direction is 0.3r, the uniformity variance of the felt body is as high as 0.049941927, which meets the uniformity requirement of the felt body.

It should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention, and are not used to limit the protection scope of the present invention. Equivalent replacements or substitutions made on the above-mentioned basis all belong to the protection scope of the present invention.

Claims (4)

1. A method of improving the uniformity of a slurry-making mat comprising the steps of:

step 1, obtaining a relation equation of radius and thickness distribution in concentric circle plaque sprayed by actual slurry; the relation equation is obtained by measuring the actual distribution condition fitting of the radius and the thickness in the concentric circles of plaques;

step 2, generating a filter screen interface; dividing grids on the filter screen interface, calibrating coordinates of each grid and numbering;

step 3, generating a simulated concentric circular plaque on the filter screen interface according to the relation equation in the step 1; setting position coordinates of initial spraying on the filter screen interface, measuring and calculating the distance between each grid of the filter screen interface and the initial spraying position, adding a digital mark on the grids in the simulated concentric circle plaque range, wherein the digital mark represents the thickness condition of the concentric circle plaque on the grid position;

step 4, the concentric circles of plaques move on the filter screen interface according to a set movement rule; the set parameters of the movement rule comprise speed movement and movement tracks; adding digital marks to grids covered when simulating concentric circular plaque movement; when concentric circular spots at different moments cover the same grid, the digital marks on the grid are accumulated;

step 5, after the movement is completed, counting the accumulated thickness of the felt formed on the filter screen interface, and evaluating the thickness distribution uniformity of the felt; after the movement is completed, counting the number mark values in each grid of the filter screen, and converting the number mark values into thickness distribution conditions of the felt body on the filter screen;

and 6, changing the setting parameters of the movement law in the step 4, and repeating the steps 4 and 5 to obtain the movement law of the atomizer for manufacturing the felt body with uniform thickness distribution.

2. The method for improving the uniformity of slurry spraying and felting according to claim 1, wherein the specific method in the step 1 is as follows: spraying slurry onto a plane filter screen at a fixed position by an atomizer to obtain slurry concentric circle plaques, measuring the average thickness of the circular plaques at different radiuses to obtain data of the radius of the circular plaques and the thickness distribution of the slurry, and fitting a relation equation of the radius and the thickness distribution in the concentric circle plaques through the data.

3. The method of improving the uniformity of a slurry spray felting process according to claim 1, wherein in said step 5, the uniformity of the thickness distribution of the mat is evaluated by measuring the variance of the uniformity of the thickness distribution of the mat.

4. A method for improving the uniformity of a slurry spray felting process according to claim 3, wherein said step 5 is performed with a uniform felt having a uniformity variance of less than 0.05 for a felt having an average thickness of 1 cm.

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