With an intelligent controller design featuring PID output, the Model 61 Boiler Blowdown System from Electro-Chemical Devices, Inc., modulates the blowdown control valve to allow the maximum level of dissolved solids regardless of load conditions for greater maintenance efficiency at lower cost.
During routine boiler operation, dissolved solids become concentrated in the tank water. As the solids increase in concentration, they may cause damage to piping, steam traps and other process equipment. Sludge also can form in the boiler, which impairs its operational efficiency by reducing its heat transfer capabilities.
To avoid these problems, the boiler water must be periodically sampled, tested and then discharged or blown down with either automated equipment, such as the Model 61 BBS, or by manual techniques. The boiler is replenished with fresh feedwater commensurate with the blowdown rate. Conductivity (TDS) sensors are utilized to determine when the boiler water must be replaced.
To avoid these problems, the boiler water must be periodically sampled, tested and then discharged or blown down with either automated equipment, such as the Model 61 BBS, or by manual techniques. The boiler is replenished with fresh feedwater commensurate with the blowdown rate. Conductivity (TDS) sensors are utilized to determine when the boiler water must be replaced.
The Model 61 BBS sample conditioner reduces water temperature prior to sample measurement. By cooling the sample, the accuracy of the conductivity (TDS) measurement improves. The conductivity measurement is made with the controller or optional two-wire transmitters (ECD’s Model T23 or T28) and the ECD Model CS10.
The Model 61 BBS features ECD’s Model C22 Controller. The C22 includes an easy-to-read local display and XY graphical plot capability. It is a line powered instrument with PID control functions, logic functions and timers. The standard Model 61 is supplied with one 4-20 mA output and two alarm relays. Up to 4 outputs and 8 relays are available as an additional option.
The C22 Controller’s 4-20 mA output can be configured as a PID control output. The proportional/
The C22’s timers also can be configured to periodically trigger a relay for bottom blowdown, which may only be needed on a weekly or monthly basis. The Model 61 BBS also can be connected directly to a distributed control system or programmable logic controller via the Model T23 or T28, 4-20 mA, two wire transmitters.
The standard conductivity (TDS) range of the Model 61 BBS CS10 sensor is 0 to 10,000 µS. It operates over a temperature range from 0 to 100°C under pressures from 0 to 75 psig.
