The automatic boiler water level controller is mainly composed of hardware and software parts to complete the functions of the control system. The hardware part is mainly composed of the water level detection circuit, drive circuit, water level indication circuit, pressure automatic control simulation, manual control, etc. The software part is mainly composed of the programs written in assembly language.
If the impurities in the boiler feedwater are not dealt with properly, carryover of boiler water into the steam system can occur. This may lead to problems elsewhere in the steam system, such as:
The quality of the water used to produce the steam in the boiler will have a profound effect on meeting the objectives such as safe operation, maximum combustion and heat transfer efficiency, minimum maintenance and long working life.
The steam boiler in the packaging plant is mainly used in the heating process before the raw paper is made into cardboard. In brief, it is using steam which contains no water in the drying process to improve the production efficiency and product quality of packaging cartons. As a result, it has high requirements for the steam and steam boiler, such as temperature, water content, rated evaporation capacity per unit time, etc., which are important parameters in the boiler selection.
Here load means, amount of steam drawn from the boiler. So when the load increases, the specific volume of the steam in the boiler increases reducing the pressure. This inturn demands for more feed water and more amount of fuel to be burnt. So, for any boiler there will be a feed water level control system put in place to measure the water level in drum. As and when the level of water in the drum reduces, the controller sends a signal to the feed water pump to start and stops when the desired water level is reached. This way the steam generation continues to maintain the desired pressure.
A water level sensor fail on a steam boiler is extremely dangerous. The low water cut of should be tested daily. If the sensor fails the boiler could turn all the water into steam, leaving the boiler dry. Without water in the boiler the flame from the burner would heat up the heating surface to extreme temperatures and would crack and damage the inside of the boiler. But that’s not the dangerous part. If water added to boiler while it is extremely hot. Once water touches the extremely hot heating service, water would immediately start to evaporate into steam. When water evaporates it expands 18x it’s original size. The boiler would explode from the sudden increase in pressure from the inside. Some in some cases, boilers that have exploded out of a building and have landed 100s of feet away.
Normally a boiler is provided with two independent sensors for emergency low water level burner cut-outs. So this would never happen. However, if it does, don't take any chances! Shut off the burners immediately!
Before you start raising the level in the boiler you have to find out if any part of the furnace walls has been overheated. If you raise the level over a glowing steel-wall then the boiler might produce more steam than the safety valves can handle and a nasty explosion would be the result.
Few parameters critical to health of the Boiler are
(4)Heat rate of the Boiler. This is a composite index of many performance indicators. Most of them will appear below.
(5)Unburnt fuel in flue gas and at boiler bottom .
(6)Flue gas furnace exit temperature.
(7)Boiler tube metal temperatures.
(8)Oxygen in flue gas.
(9)Imbalances in flue gas temperature over a cross section.
(10)Spray water consumption in Super heater and Reheater.
(11)Heat radiation from insulation.
The above all affects the performance of the boiler.
