Factors affecting the glass liquid flow in a glass furnace ??

Previously we discussed the factors that affect the flow of liquid glass in a glass furnace

(1) Overall temperature and temperature gradient (you can see it in the dynamics two days ago)

Today's focus is on combustion energy distribution and flame shape.

1. Combustion energy distribution

Fuel combustion is one of the main ways of obtaining energy in a glass furnace. Gas is fed into the glass furnace for combustion through flame lances, and the energy is mainly transferred by heat radiation to melt raw materials and warm up the glass liquid. The distribution ratio of gas consumption on each gun determines the energy generated by the combustion of each gun. It is also a direct influence on the distribution of the temperature gradient in the flame space.

The common temperature gradient is close to the middle of the glass furnace behind the part of the highest temperature, to both sides of the lower in turn, the formation of hot spots and 2 circulation.

In a glass furnace structure with a dedicated clarifier, the flame space temperature can develop a gradient pattern. This is shown in the diagram below.

2. flame shape

Since it mainly relies on flame radiation to transfer heat energy, the closer to the flame of the raw material or glass liquid, the higher the energy gained. Therefore, the length and shape of the flame directly affect the temperature field distribution in the glass furnace. The shorter and narrower the flame, the smaller its coverage, the more concentrated energy released, and energy utilization is relatively low.

Flame shape depends on the type of spray gun and the amount and ratio of oxygen and gas. Reasonable configuration of the above parameters, so that the length of the flame on one side covers about one-third of the width of the glass furnace, and the flame is a bright, stable shape, moderate rigidity, along the horizontal direction of the spray or slightly downward sloping.

Different flame shapes are shown in Fig. 3

The effect of flame length on the temperature field of the vitreous liquid is shown in Fig. 4.

3. Suitable flame length

Mathematical simulation based on the actual production situation can be seen, the appropriate length of the flame can cover as much as possible the surface of the glass liquid, and its radiation temperature is shown in Figure 4(a).

At this time, the glass liquid of the glass furnace in the lateral direction of the furnace is affected by the flame to a uniform degree, the left and right temperatures are basically the same, and the depth direction isotherms are more parallel. Whether the doghouse raw material melting speed or subsequent glass liquid heating speed is more uniform, the glass liquid is easier to homogenize.

As the flame covers a large area, the utilization rate of gas heat is higher, which can reduce the gas consumption to a certain extent; meanwhile, it can effectively reduce the lateral convection of the glass liquid caused by the temperature difference, and reduce the scouring of the sidewall blocks.

• When the flame is too short, its radiation temperature is shown in Fig. 4(b). Due to the small flame radiation area, the glass liquid is not uniformly heated, and the temperature of the glass liquid in the transverse direction of the glass furnace shows a trend of low in the middle and high on both sides. In contrast, the transverse temperature difference is larger, resulting in stronger lateral convection of the glass liquid, accelerating the thermal erosion of the glass liquid on the refractory material. At the same time, due to the centralized flame heating, the gas heat utilization efficiency is low.
• The flame is too long will make the left and right flame gas flow direct contact, high-temperature gas flow collision and change direction, flow in all directions, resulting in a higher temperature at the centerline of the glass furnace. It will also increase the temperature of the top of the crown, and in severe cases, it will erode the arch block, which needs to be strictly controlled in actual use.

HENAN SNR Refractory Co., Ltd (SNR) has been dedicated to glass furnace design, refractory bricks research, development, manufacturing, furnace construction, innovation, and upgrading for 30 years.

If you have any needs for refractory blocks, please do not hesitate to contact me!

?? Web: www.snr-azs.com

?? Email: [email protected]