CCI Delivers a Smooth Solution

Advance Agro Public Company Ltd. is a Thai manufacturer of printing and writing paper. The company produces 427,000 tons per year (tpy) of elementary chlorine free bleached pulp which in turn is used for the production of high quality printing and writing paper on two custom paper machines.

A stable supply of steam at the optimal pressure and temperature to the paper machines enhances productivity and paper quality. Temperatures that are too low cause paper web breaks in the drying section of the paper machine. Temperatures that are too high can cause fires there. Advance Agro suffered from disruptive temperature variations until CCI’s steam conditioning valves were installed

At Advance Agro electrical power is generated from the recovery boiler, which is fueled by the lignin solution from the pulp digesting system, as well as from the power boiler. This is also fueled by other wood wastes such as bark. Steam from the boilers is used to turn the turbines in addition to heating the cylinders on the paper machines used for drying the paper.

The steam is heated in the boilers and cooled inside the valve by mixing with water. The original valve had independent spraywater and actuation controls. This created a time lag, causing unwelcome variations in output steam temperature. Apart from lower quality paper, this temperature variation also caused erosion of the valve and serious subsequent steam leakage.

To provide the paper machines with a steady steam flow, at a pre-determined pressure and temperature requires valves capable of withstanding intense steam pressure and temperature changes, ranging from 85 bar to 3.5 bar and 380°C to 160°C (716°F to 320°F).

CCI's VST-SE steam conditioning valves were installed to solve these problems and achieve the requirements. Their built-in water proportioning system reacts instantaneously to temperature change, eliminating the variations in the output steam temperature. This enhanced both paper quality and overall plant productivity. Since the installation of the CCI valves, paper machine reliability has improved greatly. Chawalit Janpetch, Project Manager of Inter Project Management Company Ltd. (a profit centre within Advance Agro Public Co. Ltd) commented, “We’ve experienced stable pressure and temperature in the 3.5 bar header. Operational availability has been very high and maintenance requirements have been virtually zero… we didn't buy a valve, but a solution.”

Published in SOLUTIONS Spring 2006