RU2125024C1 - Equipment manufacturing fiber from mineral melt - Google Patents

Abstract

FIELD: production of heat insulation materials. SUBSTANCE: equipment incorporates guiding trough, rotary cup with grooves uniformly arranged on its internal surface and directed from center of cup to its periphery and ring blasting head. Grooves are made at angle equal to α = arccosv $\genfrac{}{}{0ex}{}{\text{2}}{\text{o}}$ +v $\genfrac{}{}{0ex}{}{\text{2}}{\text{k}}$ -v $\genfrac{}{}{0ex}{}{\text{2}}{\text{а}}$ /2•v_o•v_k, where α - is angle included between vectors of relative velocity of jet of melt in groove and backward continuation of vector of circumferential velocity of rotation of cup ( with 60 deg<60^°<α<160^°;<160 deg ), v_o is circumferential velocity of rotation of cup; v_k is relative velocity of jet of melt in groove; v_a is absolute velocity of jet of melt across groove outlet. EFFECT: improved quality and reduced diameter of fiber, increased productivity. 5 dwg

Description

 The invention relates to the industry of thermal insulation materials and can be used to produce mineral fiber.

 A device for the manufacture of mineral fibers, including a guide tray, a rotating bowl and an annular blasting head (Goryainov K.E. et al. Technology of mineral thermal insulation materials and light concrete. - M .: Stroyizdat, 1966, pp. 91-96). This device allows you to get fiber due to the initial centrifugal splitting of the melt in a rotating bowl into mineral formations: trickles, films and droplets and the subsequent drawing of fibers from them by the energy carrier flow coming out of the blasting head.

 The fiber obtained using this device has a significant variation in diameter. In addition, there is a large number (25%) of non-fibrous inclusions - “kings” in the fiber, which degrade the quality of the fiber. Also, a significant amount of heavy particles of the melt flies out of the energy carrier and falls into the waste (22-28%). Thus, the known device has the following disadvantages: low quality of the produced fiber and low productivity.

 A device for producing fiber from a mineral melt is known, including a directing flow, a rotating bowl and a blasting head, the bowl being made with grooves uniformly located on its inner surface and directed from the center of the bowl to its periphery along arcs curved to the opposite direction of rotation of the bowl (USSR copyright certificate N 1735214, A1, class C 03 B 37/04, 1992).

 This device is the closest in technical essence to the proposed device and is selected as the closest analogue.

 Due to the presence of grooves in the bowl, the melt is evenly split into streams, which are then pulled into the fibers by an energy carrier stream. The quality of the fiber obtained using this device is much better, since it has a smaller variation in diameter, the amount of non-fibrous inclusions in it, as well as waste during its production, is insignificant.

 However, this device has a drawback - the melt jets flowing from the grooves of the bowl have a low absolute speed, since the relative velocity vector of the melt jet, which coincides with the streamline of the melt in the grooves, is directed to the side opposite to the circumferential velocity of rotation of the bowl directed to the side rotation of the bowl tangent to its circumference. And with the vector addition of velocities, the absolute velocity assumes a low value, as a result of which the cross-sectional area of the melt jet increases, and therefore, the fiber diameter increases. In addition, from the condition of steady flow (constant flow), with increasing diameter, the fiber yield decreases.

 Thus, a consequence of this drawback is the low quality of the fiber and low productivity of the device.

 The problem solved by the invention is to improve the quality of the fiber and increase the productivity of the device.

где
α - угол между вектором относительной скорости струи расплава в канавке и обратным продолжением вектора окружной скорости вращения чаши, причем 60^o < α < 160^o;
v_о - окружная скорость вращения чаши;
v_к - относительная скорость струи расплава в канавке;
v_а - абсолютная скорость струи расплава на выходе из канавки.This object is achieved in that in a device for manufacturing fiber from mineral melt, including a guide tray, a rotating bowl with grooves uniformly located on its inner surface and directed from the center of the bowl to its periphery, and an annular blowing head, the angle at which the grooves are directed is equal

Where
α is the angle between the vector of the relative velocity of the melt jet in the groove and the reverse continuation of the vector of the peripheral speed of rotation of the bowl, with 60 ^o <α <160 ^o ;
v _about - peripheral speed of rotation of the bowl;
v _to - the relative speed of the jet of melt in the groove;
v _a is the absolute velocity of the melt jet at the outlet of the groove.

 In FIG. 1 shows a device for producing fiber, a longitudinal section, in FIG. 2, 3, 4, 5 - variants of the inner surface of the bowl with a different direction of the grooves.

 A device for manufacturing fiber from a mineral melt includes a guide tray 1 for supplying the melt, a bowl 2 rotating on a horizontally mounted drive shaft 3, and an annular blowing head 4. On the inner surface 5 of the bowl 2 are grooves 6 directed from the center of the bowl 2 to its periphery at a certain angle.

где
α - угол между вектором относительной скорости струи расплава в канавке и обратным продолжением вектора окружной скорости вращения чаши, причем 60^o < α < 160^o;
v_о - окружная скорость вращения чаши,
v_к - относительная скорость струи расплава в канавке,
v_а - абсолютная скорость струи расплава на выходе из канавки.The angle at which the grooves 6 are directed is determined by the formula (derived from the cosine theorem)

Where
α is the angle between the vector of the relative velocity of the melt jet in the groove and the reverse continuation of the vector of the peripheral speed of rotation of the bowl, with 60 ^o <α <160 ^o ;
v _about - the peripheral speed of rotation of the bowl,
v _to - the relative speed of the jet of melt in the groove,
v _a is the absolute velocity of the melt jet at the outlet of the groove.

The angle α varies from 60 ^o to 160 ^o . When α <60 ^{o, the} groove 6 will be directed so that the geometric sum of the vector of the circular velocity of rotation of the bowl 2, directed in the direction of rotation of the bowl 2 tangentially to its circumference, and the vector of the relative velocity of the melt jet in the groove 6, directed in the opposite direction, i.e. the absolute speed of the melt stream at the outlet of the groove 6 will take values lower than the peripheral speed of rotation of the bowl 2. And this means that there will be a decrease in the performance of the device, which is undesirable. At α> 160 ^{o, the} absolute velocity of the melt jet at the outlet of the groove 6 will take on some of the large values, however, it is very difficult to solve the grooves from such a technical angle. Therefore, the limit of change of angle α is limited to 160 ^o .

In FIG. 2 shows a bowl 2, on the inner surface 5 of which the grooves 6 are directed at an angle α from 60 ^° to 90 ^° , that is, in the direction opposite to the direction of rotation of the bowl 2.

In FIG. 3 grooves 6 are directed at an angle α = 90 ^o , that is, radially with respect to the center of the bowl 2.

In FIG. 4 grooves 6 are directed at an angle α from 90 ^o to 160 ^o , that is, in the direction of rotation of the bowl 2.

In FIG. 5 grooves 6 are directed along arcs curved in the direction of rotation of the bowl 2, and the angle α at which the melt exits the groove 6 varies from 60 ^° to 160 ^° .

 For convenience, the images in FIG. 2, 3, 4, 5, the addition of speeds conditionally performed in two-dimensional space (in the plane), while this addition should be performed in three-dimensional space.

The more the angle changes from 60 ^o to 160 ^o , under which grooves 6 are directed, the greater the absolute speed of the melt stream (see Kulmach P.P., Hydroaeromechanics, - L .: VVITKU, 1972, p. 559-562), and the smaller their diameter at the exit of the grooves 6, and therefore the diameter of the resulting fibers. In proportion to the decrease in the diameter of the fibers with a constant flow rate (flow) of the melt from the smelter, the yield of the resulting fibers also increases.

 The device operates as follows.

The mineral melt flowing from the melting unit is fed to a guide tray 1, from which it enters the inner surface 5 of the bowl 2. Under the action of centrifugal force, the melt, spreading with a thin film on the inner surface 5 of the bowl 2 and moving to its periphery, gets into evenly spaced grooves 6. Grooves 6 are directed from the center of the bowl 2 to its periphery, and to ensure a high speed of the melt stream at the outlet of the grooves 6, the angle α at which they are made varies from 60 ^° to 160 ^° . The melt streams move along the grooves 6, constantly decreasing in cross section, to the periphery of the bowl 2 and go off from it, where they acquire an absolute speed equal to the vector sum of the relative speed of the melt streams, directed along the melt stream line in the grooves 6 and the peripheral speed of rotation of the bowl 2, directed in the direction of rotation of the bowl 2 tangentially to its circumference. The flow of energy coming out of the blasting head 4 picks up trickles of melt, changes their trajectory by about 90 ^° , draws them to a final diameter and cools them to solidification into fibers.

The achievement of the solution of the problem is the following: when the angle α, under which the grooves are directed, within 60-160 ^o , there is an increase in the absolute speed of the melt jets at the exit of the grooves. This leads to a decrease in the diameter of the melt streams, as well as the fibers obtained from them (by 10-15%), which improves the quality of the fiber. In addition, the productivity of the device is increased by increasing the fiber output from the melt (by 12-15%), and technological parameters such as: bowl rotation frequency, energy carrier feed rate, viscosity, etc. remain unchanged.

 The bowl for splitting the melt is made of a solid metal, with a heat insulating substrate or a water-cooled cavity (not shown in Fig. 1).

Claims (1)

A device for manufacturing fiber from a mineral melt, including a guide tray, a rotating bowl with grooves uniformly located on its inner surface and directed from the center of the bowl to its periphery, and an annular blasting head, characterized in that the angle at which the grooves are directed is

where α is the angle between the vector of the relative velocity of the melt jet in the groove and the reverse continuation of the vector of the peripheral speed of rotation of the bowl, with 60 <α <160 ^° ;
v _about - peripheral speed of rotation of the bowl;
v _to - the relative speed of the jet of melt in the groove;
v _a is the absolute velocity of the melt jet at the outlet of the groove.

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