CN114750279A - Low-temperature drying process for sintered wallboard - Google Patents

Abstract

The invention discloses a low-temperature drying process of a sintered wallboard, which relates to the field of manufacturing of modular wallboards, and is characterized in that the wallboard begins to be dehydrated and shrunk to different degrees from the beginning of extruding a wet blank wallboard.

Description

Low-temperature drying process for sintered wallboard

Technical Field

The invention belongs to the field of manufacturing of module wallboards, and particularly relates to a low-temperature drying process of a sintered wallboard.

Background

During the manufacturing process of the sintered wallboard, firstly, the wet green wallboard is extruded by a brick machine to be manufactured, then, the wet green wallboard is placed on a kiln car, is naturally dried and shaped in the shade due to the change of external temperature and humidity, is directly sent into a tunnel drying kiln to be dried, and finally enters a tunnel roasting kiln to be sintered to manufacture the sintered wallboard; the current common drying process mainly adopts natural drying in the shade and a tunnel drying kiln for drying; but the wet blank loses a large amount of moisture uncontrollably in the process of natural drying in the shade and drying and shaping in a tunnel drying kiln, and the size of the wet blank is shortened due to the moisture loss and the blank is easy to crack and deform;

the longer the fired wallboard size, the higher the incidence of the defects, and how to solve the problems becomes a technical overcoming difficulty in producing longer and larger-size wallboards.

Disclosure of Invention

In order to solve the above problems in the prior art, the present invention aims to provide a low temperature drying process for sintered wallboard.

The technical scheme adopted by the invention is as follows:

a low-temperature drying process of a sintered wallboard comprises the following steps:

s1: surface spraying, wherein the outer surface of the wet blank wallboard formed by extrusion molding is subjected to spraying treatment, and the spraying material comprises engine oil;

s2: standing, namely standing the wet blank wallboard subjected to spraying treatment on a drying bracket vehicle with a freely-rolling carrier roller;

s3, drying at low temperature, namely, conveying the drying bracket vehicle into a pre-drying chamber provided with an exhaust fan, wherein the low-temperature drying comprises five stages;

the first stage, air-drying for 10-15 h at the temperature of 20 ℃;

in the second stage, air-drying for 10-15 h at the temperature of 25 ℃;

the third stage, air-drying for 10-15 h at the temperature of 30 ℃;

fourthly, air-drying for 10-15 hours at the temperature of 35 ℃;

fifthly, air-drying for 10-15 h at the temperature of 40 ℃; obtaining a semi-dry blank;

s4: high-temperature drying, namely sending the semi-dried blank into a tunnel drying kiln for high-temperature drying, wherein the high-temperature drying comprises four sections of drying processes which are sequentially carried out, the first section of drying process is that the semi-dried blank is dried for 4.5 to 5 hours at room temperature,

the second stage of drying process is drying the semi-dry blank for 4.5-5 h at 50-60 ℃,

the third drying process is drying the semi-dry blank for 4.5-5 h at the temperature of 100-120 ℃,

and the fourth drying process is to cool the semi-dried blank to room temperature to obtain a dried blank.

Further, in step S2, exhaust fans are disposed on a set of walls opposite to each other in the pre-drying chamber, and the wet blank wall boards correspond to the exhaust fans one by one.

Further, the pre-drying chamber is divided into five sections, each section can accommodate five drying carts, and a lifting door is arranged between each section to independently form a closed space.

Further, dry bracket car includes movable frame and installs the bearing structure on movable frame, is provided with a plurality of backup pads on the bearing structure, and equidistant setting on a plurality of backup pads along the vertical direction of bearing structure, impartial interval is provided with a plurality of mounting panels in a plurality of backup pads, installs the bearing roller group between the two adjacent mounting panels, and bearing roller group includes the bearing roller of a plurality of equidistant settings, and a plurality of bearing rollers between the adjacent bearing roller group are crisscross to be set up, and every bearing roller is all freely rotatable.

Furthermore, a plurality of carrier rollers are all made of stainless steel tubes.

Furthermore, a plurality of supporting rollers are all made of iron pipes.

Furthermore, the movable frame, the supporting structure, the mounting plate and the supporting plate are all made of steel.

Further, the first stage of drying process is drying the semi-dry blank at room temperature for 5h, the second stage of drying process is drying the semi-dry blank at 50 ℃ for 5h, the third stage of drying process is drying the semi-dry blank at 120 ℃ for 4.5h, and the fourth stage of drying process is cooling the semi-dry blank to room temperature to obtain the dry blank.

The invention has the beneficial effects that:

the invention provides a low-temperature drying process of a sintered wallboard, which is characterized in that the wallboard begins to be dehydrated and shrunk to different degrees from the beginning of extruding a wet blank wallboard, and the air is discharged by a corresponding exhaust fan for convective drying in a constant temperature range of a pre-drying chamber, so that the internal stress release of the wet blank of the wallboard can be assisted, the cracking or surface abnormity of the water blank of the wallboard in the dehydration and drying process can be prevented, and the flatness and integrity of the wallboard can be ensured;

in addition, an exhaust fan arranged in the pre-drying chamber corresponds to each wallboard on the drying bracket vehicle, through convection exhaust, the outer part of a wet blank of the wallboard and the inner part of a hole can be fully contacted with the outside air, the dehydration is uniform, the exhaust speed can be adjusted by the exhaust fan, the dehydration speed of the wallboard is further controlled, the dehydration and drying of the wallboard are favorably controlled, the dehydration balance effect is achieved, through the staged low-temperature drying of the semi-dry blank in the pre-drying chamber, the temperature change is slow, the stress in the wallboard drying process can be effectively released, and the wallboard is prevented from being deformed or cracked in the drying process;

meanwhile, the wet blank is sprayed before drying, and the size change caused by too fast dehydration of the wallboard can be effectively prevented through oil spraying materials of a spraying machine, so that the problem of deformation generated in the drying process of the wet blank wallboard is effectively prevented. Even facing to the wallboard with larger size, the drying method of the invention can be well applied, thereby overcoming the problem that the tunnel kiln sintered wallboard can not produce products with large size, and simultaneously meeting the national requirement for the assembled wallboard.

Drawings

FIG. 1 is a schematic flow diagram of the present invention.

Fig. 2 is a schematic view of a drying carrier vehicle.

In the figure: the device comprises a movable frame, 2 side plates, 3 rollers, 4 supporting structures, 5 mounting plates, 6 carrier rollers and 7 supporting plates.

Detailed Description

In this embodiment, as shown in fig. 1, a low temperature drying process for sintered wallboard comprises the following steps:

s1: surface spraying, namely spraying the outer surface of the wet blank wallboard obtained in the step S2, wherein the spraying material comprises engine oil;

s2: standing, namely standing the wet blank wallboard subjected to spraying treatment on a drying bracket vehicle with a freely-rolling carrier roller;

s3, drying at low temperature, namely, conveying the drying bracket vehicle into a pre-drying chamber, arranging exhaust fans on a group of opposite walls of the pre-drying chamber, wherein wet blank wall plates correspond to the exhaust fans one by one, and the wet blank wall plates are air-dried in the pre-drying chamber for 50-75 hours, wherein the low-temperature drying comprises five stages;

the first stage, air-drying for 10-15 h at the temperature of 20 ℃;

in the second stage, air-drying for 10-15 h at the temperature of 25 ℃;

the third stage, air-drying for 10-15 h at the temperature of 30 ℃;

fourthly, air-drying for 10-15 hours at the temperature of 35 ℃;

fifthly, air-drying for 10-15 h at the temperature of 40 ℃; obtaining a semi-dry blank; the pre-drying chamber can create an environment with a constant temperature range (the temperature is controlled to be 20-30 ℃) and exhaust air through the exhaust fan to carry out air convection drying, and the pre-drying chamber is mainly used for assisting the release of the internal stress of the water blank of the wallboard and preventing the occurrence of cracking or surface abnormity of the wet blank of the wallboard in the dehydration drying process. Specifically, the pre-drying chamber is divided into five sections, each section can accommodate five drying vehicles, and a lifting door is arranged between each section to independently form a closed space.

S4: high-temperature drying, namely conveying the semi-dry blank into a tunnel drying kiln for high-temperature drying, gradually heating the semi-dry blank from room temperature to 120 ℃ within 18-20 h, and then cooling to room temperature to obtain a dry blank; specifically, the high-temperature drying comprises four drying processes which are sequentially carried out, wherein the first drying process is to dry a semi-dry blank at room temperature for 4.5-5 hours, the second drying process is to dry the semi-dry blank at 50-60 ℃ for 4.5-5 hours, the third drying process is to dry the semi-dry blank at 100-120 ℃ for 4.5-5 hours, the fourth drying process is to cool the semi-dry blank to room temperature to obtain a dry blank, the high-temperature drying process is divided into four stages, and the stress of the wall board in the semi-dry blank state in the drying process can be effectively released by relatively relieving the temperature change, so that the problem of wall board deformation of the semi-dry blank in the drying process can be effectively prevented.

Specifically, the preparation of the wet green wallboard comprises the following steps:

selecting shale, coal gangue and building garbage to prepare raw material powder, adding water into the raw material powder, stirring to form a mixture, and naturally fermenting the mixture for about 72 hours to obtain an aged material; and conveying the aged material into an extruder through the working procedures of squeezing, stirring, double-roller squeezing, pugging and the like to prepare the wet-blank wallboard.

Specifically, the selected construction waste, shale and coal gangue are respectively ground into 60-200 mesh powder, and the coal cinder is selected and ground into 200-300 mesh powder for later use; mixing the construction waste powder and the coal cinder powder according to the weight ratio of 3:5-2:3, gradually adding a proper amount of water while stirring to prepare a mixture with the water content of 14-16%, and preparing a wet blank wallboard through an extruder; wherein the construction waste is concrete blocks, stone, gravel or waste bricks.

In this embodiment, as shown in fig. 2, the drying carrier cart according to the present invention includes a movable frame 1 and a support structure 4 installed on the movable frame 1, a plurality of support plates 7 are disposed on the support structure 4, the plurality of support plates 7 are disposed at equal intervals in a vertical direction of the support structure 4, a plurality of mounting plates 5 are disposed at equal intervals on the plurality of support plates 7, a carrier roller group is installed between two adjacent mounting plates 5, the carrier roller group includes a plurality of carrier rollers 6 disposed at equal intervals, the plurality of carrier rollers 6 between adjacent carrier roller groups are disposed in a staggered manner, and each carrier roller 6 can rotate freely. Through equidistant a plurality of bearing rollers 6 that set up on mounting panel 5, a plurality of bearing rollers 6 homoenergetic free rotation are used for preventing the wet base wallboard of founding the sign indicating number on the bearing roller 6, when wet base wallboard syneresis, because bearing roller 6 can the free roll, can assist the inside stress release of wet base wallboard, prevent that the condition that fracture or bending deformation appear in the wet base wallboard dehydration drying process from taking place, can guarantee the roughness of wallboard.

Meanwhile, the carrier rollers 6 are divided into carrier roller groups and arranged among the mounting plates 5, the carrier rollers 6 between the adjacent carrier roller groups are arranged in a staggered mode, gaps between the two adjacent carrier rollers 6 and the carrier roller groups are used as air flow channels, the contact mode between the wall board and the carrier rollers 6 is line contact, the contact area is small, the water blank of the wall board can be fully contacted with the outside air, and water loss drying of the water blank is facilitated.

In this embodiment, as shown in fig. 2, the supporting structure 4 includes a plurality of supporting pillars, the supporting pillars are uniformly distributed in two groups, each group of supporting pillars is respectively disposed at two ends of the movable frame 1, and two ends of the supporting plate 7 are respectively connected to two groups of supporting pillars.

In this embodiment, as shown in fig. 2, each group of support columns includes three support columns, the three support columns of each group of support columns are respectively disposed at two sides and a middle position inside the movable frame 1, and the support columns near two sides of the movable frame 1 are connected to the support plate 7.

In this embodiment, as shown in fig. 2, two sets of supporting plates 7 are connected to the supporting column, the two sets of supporting plates 7 are respectively disposed at the middle and top of the supporting column, each set of supporting plates 7 includes two supporting plates 7, the two supporting plates 7 of each set of supporting plates 7 are respectively disposed on the supporting column near two sides of the movable frame 1, that is, an upper layer and a lower layer of brackets are disposed on the supporting column in total, the two layers of brackets can be used independently, and wet blank wallboards can be placed on each layer.

In this embodiment, as shown in fig. 2, the movable frame 1 includes four side plates 2 and four rollers 3, the four side plates 2 form a rectangular frame, roller fixing seats are respectively disposed on two side walls of the rectangular frame, the rollers 3 are mounted on the roller fixing seats, the four rollers 3 are respectively disposed at two ends of the two roller fixing seats, and the rollers 3 can be used for driving the movable frame 1 to move under the condition of applying an external force, so that the present invention is convenient to enter and exit the pre-drying chamber.

In this embodiment, the supporting structure 4 is provided with the plurality of supporting plates 7, the plurality of supporting plates 7 are arranged at equal intervals in the vertical direction of the supporting structure 4, that is, the plurality of supporting plates 7 are distributed in multiple layers in the vertical direction of the supporting structure 4, the plurality of mounting plates 5 are arranged on the plurality of supporting plates 7 at equal intervals between two supporting plates 7 of each layer, the carrier roller group is arranged between two adjacent mounting plates 5 and comprises a plurality of carrier rollers 6 arranged at equal intervals, so that the wet blank wallboard accommodating device can accommodate a plurality of wet blank wallboards at the same time, and the wet blank wallboards are arranged in a layered manner. The invention can dry a plurality of wet blank wallboards simultaneously, and the wet blank wallboards can not generate mutual interference, thereby improving the drying efficiency to a great extent.

In this embodiment, the carrier rollers 6 are made of stainless steel tubes, the stainless steel tubes have brightness close to a mirror surface, cannot be bonded with a wet blank wallboard to be dried, cannot damage the wet blank wallboard, and has good heat resistance, corrosion resistance and mechanical properties, so that the carrier rollers have the advantages of easiness in forming and low cost, and the stainless steel has series of characteristics of excellent corrosion resistance, formability, compatibility, toughness and the like, and can adapt to wet blank wallboards made of various materials.

In other embodiments, the carrier rollers 6 are made of iron pipes, and are not easy to deform due to stable chemical properties, high thermal conductivity, small thermal expansion coefficient, good wear resistance and high hardness, and cannot be bonded with wet blank wallboards to be dried, so that the carrier rollers are low in cost and can adapt to wet blank wallboards of various materials.

In other embodiments, bearings are installed at both ends of the stainless steel pipe or the iron pipe, so that the idler 6 has less resistance when rotating, thereby realizing free rotation.

In the present embodiment, as shown in fig. 2, the movable frame 1, the support structure 4, the mounting plate 5 and the support plate 7 are made of carbon steel, which can withstand high temperatures and is manufactured at low cost.

In the embodiment, each pre-drying chamber comprises five temperature sections, each temperature section corresponds to one stage in the low-temperature drying step, namely, the temperature sections are calculated from the inlet of the pre-drying chamber, the first temperature section to the fifth temperature section sequentially correspond to the first stage to the fifth stage of the low-temperature drying, each temperature section meets the drying temperature by setting different exhaust fan powers, and the exhaust fan powers in the first temperature section to the fifth temperature section are gradually reduced; simultaneously, five drying bracket cars can be held simultaneously in every temperature district, and when a drying bracket car entered into the first temperature interval, every 2 ~ 3h, this drying bracket car advanced a parking stall, after the interval 10 ~ 15h, entered into the second temperature interval to analogize.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or may be connected through the use of two elements or the interaction of two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Although embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are exemplary and not to be construed as limiting the present invention, and that changes, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims (8)

1. A low-temperature drying process of a sintered wallboard is characterized in that: the method comprises the following steps:

s1: surface spraying, wherein the outer surface of the wet blank wallboard formed by extrusion molding is subjected to spraying treatment, and the spraying material comprises engine oil;

s2: standing, namely standing the wet blank wallboard subjected to spraying treatment on a drying bracket vehicle with a freely-rolling carrier roller;

s3, drying at low temperature, namely, conveying the drying bracket vehicle into a pre-drying chamber provided with an exhaust fan, wherein the drying at low temperature comprises five stages;

the first stage, air-drying for 10-15 h at the temperature of 20 ℃;

in the second stage, air-drying for 10-15 h at the temperature of 25 ℃;

the third stage, air-drying for 10-15 h at the temperature of 30 ℃;

fourthly, air-drying for 10-15 hours at the temperature of 35 ℃;

fifthly, air-drying for 10-15 h at the temperature of 40 ℃; obtaining a semi-dry blank;

s4: and (3) high-temperature drying, namely sending the semi-dry blank into a tunnel drying kiln for high-temperature drying at the drying temperature of 80-120 ℃ for 18-20 h to obtain a dry blank.

2. The low-temperature drying process of sintered wallboard according to claim 1, wherein in step S2, exhaust fans are disposed on a set of walls opposite to each other in the pre-drying chamber, and the wet green wallboard is in one-to-one correspondence with the exhaust fans.

3. The low-temperature drying process of sintered wallboard according to claim 1, wherein the pre-drying chamber is divided into five sections from the inlet to the outlet, each section can accommodate five drying carts, a lifting door is arranged between each section to independently form a closed space, and each section corresponds to one stage of low-temperature drying.

4. The low-temperature drying process of the sintered wallboard according to claim 1, wherein the drying bracket vehicle comprises a movable frame and a supporting structure mounted on the movable frame, the supporting structure is provided with a plurality of supporting plates, the plurality of supporting plates are equidistantly arranged along the vertical direction of the supporting structure, a plurality of mounting plates are equidistantly arranged on the plurality of supporting plates, a carrier roller group is mounted between every two adjacent mounting plates, the carrier roller group comprises a plurality of carrier rollers which are equidistantly arranged, the plurality of carrier rollers between every two adjacent carrier roller groups are staggered, and each carrier roller can freely rotate.

5. The process of claim 4 wherein said plurality of idlers are formed of stainless steel tubing.

6. The process of claim 4 wherein the plurality of idlers are made of iron tubes.

7. The process of claim 4, wherein the movable frame, the support structure, the mounting plate and the support plate are made of steel.

8. The low-temperature drying process of the sintered wallboard according to claim 1, wherein the first drying process in the tunnel kiln is drying the semi-dried blank at room temperature for 5h,

the second stage of drying process is drying the semi-dry blank for 5 hours at the temperature of 50 ℃,

the third drying process is drying the semi-dry blank for 4.5 hours at the temperature of 120 ℃,

and the fourth drying process is to cool the semi-dried blank to room temperature to obtain a dried blank.

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