JPS5832079A - Fire resistant heat insulating spray material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION One of the current methods of constructing castable refractories is blowing, which involves quickly transporting a large amount of material to a distant place or a high place using a hose. Traditionally, this method was mainly used for constructing chimneys and flues, but recently it has been used to shorten the construction period and
It is used in the construction of hot blast furnaces, hot air pipes, petrochemical furnaces, etc. for blast furnaces to improve furnace wall performance. Currently, this spraying method involves loading the spraying material for fireproof insulation as a dry powder or mixing it with a small amount (2 to 3% by weight) of water into a spraying machine using a pressure fluctuating discharge method, and then using compressed air. There are two methods: dry spraying, in which slurry is sent through a rubber hose, mixed with water that is pumped separately through a nozzle at the end of the hose, and slurry is mixed in advance with an appropriate amount of water in a mixer, and then the slurry is loaded into a spraying machine using a forced discharge method. There is a wet spraying method in which air is mixed with compressed air sent from a separate hose through a nozzle at the end of the feed hose through a rubber hose. These methods require water or compressed air to be mixed in the nozzle, so the nozzle operator must hold and operate two hoses, which requires a lot of effort, and requires adjustment of the water or compressed air to be added to improve bonding efficiency. It requires a high degree of skill, and the dry method generates a lot of dust during construction, which is bad for the working environment, while the wet method has drawbacks such as not being able to obtain a sufficient thickness.

In order to eliminate these drawbacks, the spraying material is made into a doughy state that is harder than the wet method, and instead of the semi-forced discharge method used for blowing hardened concrete, the hardened wet method 1 method is considered, in which the spraying material is sprayed using a machine. Sprayed materials for fireproof insulation were too sticky and could cause blockages, pulsation, and separation within hoses, so they were not put to practical use.

Spraying is the flow of materials inside the hose during construction.In the dry method, the materials are uniformly mixed and suspended in the air, while in the wet method, the slurry is sprayed inside the hose like a liquid. It is pumped under pressure and flows smoothly.

On the other hand, in the hardening wet method, the hardening material forms a lump shape, alternates with air, and flows through the hose at a short pitch, and the material is thought to be pushed forward by the difference in air pressure between the front and rear. In the hardening wet method 1, it is necessary to allow the material to flow smoothly within the hose in this state. In other words, it is required that the hardened material forming the nodule should slide well between itself, and that the hardened material should slide well against the inner surface of the hose. If this condition is not met, the flow inside the hose will deteriorate, and as mentioned above, the flow may block the port, pulsate within the hose, or
Separation (separation of the bones 44 and binder) occurs, making smooth construction impossible. In particular, if the material separates, the state of the material being blown out from the nozzle will repeat from coarse aggregate to muddy water with a lot of fine particles to coarse aggregate, which may cause the construction body to become uneven or cause blockages.

The object of the present invention is that when hardened, the bond between the aggregate and binder is sufficient and slips well, preventing blockage and pulsation within the hose.
It is an object of the present invention to provide a fireproof material that does not cause V, generates little dust, and has good adhesion. In other words, the hardened wet fireproofing spray material of the present invention has a specific particle size composition, and the materials include fireproof and heat insulating aggregate to provide fireproof properties, alumina cement to provide hardening properties, and adhesive and hose interior materials. It consists of a viscosity-imparting material that improves slippage. These materials were mixed in the following proportions.

As the fireproof and heat-insulating aggregate in this invention, clay lightweight chamotte, anorthic lightweight chamotte, porous lightweight method, and lightweight magnesia spheres are used.

Alumina cement (particle size ggμ or more T) is an alumina cement for refractories, and is mixed in order to impart hardening properties to spray materials. The amount of alumina cement added to the aggregate/θ0 heavy bond section for fireproof insulation is k.

~/θ0 parts by weight. If the amount of alumina cement is more or less than this, the strength of the sprayed layer will be lower.

The viscosity-imparting agent used to impart adhesion to the sprayed material may not necessarily require anything other than water by increasing the fine powder (particle size/SOμ or less) of the aggregate, but it is possible to This is to improve adhesion, prevent separation within the hose, and improve adhesion.

Adding viscosity - Materials include water, kaolin, Kibushi clay, Frog F
j Viscous, inorganic substances such as bentonite, gum arabic, dextrin, carboxylmethyl cellulose,
Organic materials such as polyvinyl alcohol and sodium polyacrylate are available, and each is used in its own flavor or as a mixture.

The amount of clay used is 0 for 700 parts by weight of aggregate due to shrinkage rate etc.
It is preferable to set the amount to 23 parts by weight. The amount of water used is total solids 1
It is usually 75 to 70 parts by weight relative to 0 θ parts by weight, although it varies depending on the water absorbency of the aggregate.

The maximum particle size of aggregate is limited by the inner diameter of the conveying hose, and the particle size of the commonly used hose with an inner diameter of 3 gmm is approximately 6.
It is 700μ.

The particle size of the aggregate is /Otgθμ or more (coarse grain), /Otg
It is necessary to divide the grains into those with a gty of O~0μ (medium grains) and those with a gty of less than 0μ (fine grains), and set the amount of coarse grains to the medium grains in the range of /~J, 3 times the weight ratio. There is. Outside this range, ejection failure will occur as shown in Table 1.

No./Table Weight Relative coarse grain 30 IlO1l-0303θ
30. 20! ;0 medium grain 30
30. 2030:1. OllOllI 15 Thin
Grain λθ 30 03030
R0 33-Rough/'Medium ratio/, A7/, 33.
2/'/, 50.7.5-0. ! ; 3.3 Discharge condition Good Good Good Good Good Bad Bad Bad or N
11 / Medium pressure / If there are many medium grains as shown below, Rine・L
Separation occurs, and if there are too many coarse particles as in (C) and (5) and (2) above, the sprayed layer will become brittle, resulting in poor quality as a refractory.

The total amount of powders that affect the flowability of the mix, i.e., aggregate fines, alumina cement, water-insoluble solid particles such as kaolin and clay in the thickening agent, is Gravimetric ratio is 1.2S・75-53 for the total amount of coarse grains and medium grains:
It needs to be in the range of l17. If the amount of fine particles (powder) is less than this, the adhesion during blowing will be poor and it is not practical, and if the amount of fine particles (powder) is more than this, the fine particles will adhere to the inner wall of the hose and block the hose. Otherwise, pulsation may occur, making it impossible to perform uniform construction.

According to the present invention, good spraying can be achieved by setting the torsion hardness within the following range.

In other words, in accordance with the flow test in the physical test method for alumina cement for refractories of JIS R--, a specimen was made from the material listed in the table, and the falling motion of the same test method was tested with 11.9 rb of 30 to 41 O evaporator. o-饋が/g O～, 200
m, +n. By making this preparation in conjunction with the above conditions, it is possible to smooth the flow of the spray material within the hose.

Next, examples of the present invention will be described.

Maximum operating temperature: SK fire resistance to withstand 3θOC
3g of refractory and insulating chamotte was used as the total aggregate and formulated as shown in Table 2.

d Table 1; 1; 0 factor 4u in the alumina cement column is W4y+
10゜n[Alumina cement disposed on part i
The section was shown.

A blowing test was conducted using Formulation H in Table 2 under the conditions shown in Table 3. The results are shown in Table 3.

Table 3 ×/ Maximum operating temperature: 300C class dry blowing example material.

×2 Number of falls that produces the flow value according to the explanation of torsion hardness above.

×3 Aggregate and fine powder separated in the hose ×9 Spraying was measured using a digital dust meter at a distance of 2m from the position.

×5 A sample of '10XllOX/OtsuQjnM was cut out from the construction body after adhesion and measured.

In addition, the bending strength in the direction perpendicular to the direction of the sprayed layer thickness Ji and the direction perpendicular to the direction of blowing is generally smaller, and in the case of dry-blown material, the difference is 3
g%, or in the case of invention H,! What about 3% and small difference in strength depending on direction? 11 lanes.

Applicant: Isolite Industries Co., Ltd. Japanese Patent Publication No. 58-32079 (4)

Claims (1)

[Claims] (+) It consists of aggregate for fireproof insulation, alumina cement, and viscosity-imparted aggregate, and the size of the aggregate for fireproof insulation is coarse particles with a size of /gθμ or more, and a size in the range of /otgO to g0μ. The weight ratio of coarse grains/medium grains in the aggregate for fireproof insulation is /~Y, and the fine grains of alumina cement for fireproof insulation aggregate are divided into medium grains and fine grains of gyθμ or less. The weight ratio is SO ~ 100 to 100 of the aggregate for fireproof insulation, and the fine grains, alumina cement, and viscosity imparting agent in the aggregate for fireproof insulation are relative to the combined amount of the coarse particles and medium grains of the aggregate for fireproof insulation. The weight/l ratio of the total amount of water-insoluble particles inside is 25. Near 5 to 33:
L7 fireproof insulation spray material.