Glass Materials and Batching
Glass contains three major categories of constituents - formers, fluxes, and network modifiers. Silicon dioxide (SiO2), or sand, is used as the former and basic constituent with soda ash (Na2CO3) as the flux. Lime (CaCO3) and dolomite (CaCO3MgCO3) are network modifiers that stabilize the chemical properties of the glass.
Batch Plant Storage
The batch plant receives the delivery of raw ingredients for glass making. Delivery of these
ingredients varies from site-to-site, particularly when the plant is installed in a country where
some of the ingredients are imported rather than domestic. The types of materials can be divided
into two principal groups: bulk ingredients including sand, cullet, soda ash, limestone, etc., and
"small ingredients" - various combinations of minor ingredients that are used to change physical
properties of glass including color, transparency, and refraction.
Batch plant storage systems are almost entirely dependent on the quantity of materials to be
stored and the period of time for delivery of replacement materials. Production demand and
delivery time of materials are critical factors in deciding how to design your batch plant.
Bath Plant Mixing
Poor materials, inefficient mixing, or excessive segregation of the batch following mixing can
adversely affect the operation of the melting furnace and quality of melt. Therefore, it is
necessary to ensure that the materials, as fed into the furnace, represent a mixture suitable
for the melting furnace. Handling of the required ingredients, their weighing and mixing,
requires special considerations. The number of ingredients, plus quantities to be handled, are
such that normal bulk handling techniques cannot normally be used.
Batch Plant Control
The degree and measure of plant control systems are a matter of economics and desired mode of
plant control. Ideally, each section of the plant should, where possible, be autonomous with
respect to its ability to function separately from other sections of the plant.
The batch house system should have a control system that will permit automatic start-up and
control of the batch plant for filling the furnace hopper as required, with automatic
cut-off as soon as the furnace hopper is full. This is usually about an 8-hour shift worth
of production needs.
