Engineering Solutions

Last few days were quite busy in closing smaller aspects of the infrastructure setup. But these smaller aspects are typically large in numbers and you end up spending a lot of time on closing them.

In the last post, I mentioned about the installation of the fogger system. Though the system was installed, the testing was still pending. After I procured the motor for the fogger, the entire system was ready to test.

The pump was switched on and voila ... the fogger system was working. But the next minute it stopped. The motor was still on... and I could hear the water flowing. And then we realised that the fogger line end caps had come off, thereby dropping the pressure in the entire line and stopping the fogger. Thinking that the end cap was not fitted properly, we again “properly” fitted the end caps. However the same sequence continued, Motor on, fogger works for a minute and then the end caps pop off..... leaving me perplexed...

Now it was time to approach this in a more scientific way. The fogger line, connections, fittings were checked ok. And then, the pressure gauge reading at the pump output, in the fogger line surprised us. The foggers were to be operated at rated pressure of 4.5 kg/cm2. But the foggers were activated when the gauge showed a pressure of 2.5kg/cm2. And as the pressure approached 4.5kg/cm2, the end caps popped off. This observation was indeed surprising since the foggers were getting activated well before the rated operating pressure.

That took me back to the drawing board, to analyse the design of fogger system. Each fogger is designed to operate at 4.5kg/cm2 and discharges 22lit/hr. With nearly 60 foggers, the discharge is about  1320 lit/hr. But the fogger pump discharges upto 1800 lit/hr, at the desired pressure of 4.5kg/cm2.

This implied excess water of 480lit/hr was getting accumulated in the fogger line, and creating the additional pressure which was getting built up in the fogger line.

Now with the problem identified, it was down to getting a solution for the same. The solution we zeroed on was to provide a return path to the excess water in the fogger line. With the pressure release valve in place the fogger system was now up and running.

Other smaller issues like connecting the main line to the power fence (as alternate power source, especially during rainy season), tweaking of the drip lines, electrical connection inside the polyhouse etc. were also completed during the last few days. Waiting for the next round of challenges that nature is going to throw at me during the rainy season.