Engineering Research Publication

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Engineering Research Publication

Inside Air Conditioning Unit

Description:
1. The coils and pipes in an air conditioning unit contain refrigerant gas. The refrigerant gas enters the compressor as warm, low-pressure gas and leaves it as hot, high-pressure gas.
2. In the condenser coils, hot, compressed refrigerant gas loses heat to the outdoor air and becomes liquid while it is still warm.
3. The warm, liquid refrigerant passes through the tiny opening of the expansion valve, expands, and partly turns to gas at a low temperature.
4. In the cooling coils, the refrigerant takes up heat from the indoor air and leaves the coils as warm, low-pressure gas.
5. The indoor air gives up heat to the refrigerant in the cooling coils and also loses moisture as it is chilled. The moisture condenses on the coils and trickles down to outside drain holes.

Mobile Phone SIM-card Architecture

Inside MCB and How MCB works.

MCBs or Miniature Circuit Breakers are electromechanical devices which protect an electrical circuit from an overcurrent. The overcurrent, in an electrical circuit, may result from short circuit, overload or faulty design. An MCB is a better alternative to a Fuse since it does not require replacement once an overload is detected. Unlike fuse, an MCB can be easily reset and thus offers improved operational safety and greater convenience without incurring large operating cost.
The principal of operation is simple. An MCB functions by interrupting the continuity of electrical flow through the circuit once a fault is detected. In simple terms MCB is a switch which automatically turns off when the current flowing through it passes the maximum allowable limit. Generally MCB are designed to protect against over current and over temperature faults (over heating).
There are two contacts one is fixed and the other moveable. When the current exceeds the predefined limit a solenoid forces the moveable contact to open (i.e., disconnect from the fixed contact) and the MCB turns off thereby stopping the current to flow in the circuit. In order to restart the flow of current the MCB is manually turned on. This mechanism is used to protect from the faults arising due to over current or over load.
To protect against fault arising due to over heating or increase in temperature a bi-metallic strip is used. MCBs are generally designed to trip within 2.5 millisecond when an over current fault arises. In case of temperature rise or over heating it may take 2 seconds to 2 minutes for the MCB to trip.

Catalyst for green biodiesel production from unrefined feedstock

Biodiesel is a sustainable liquid fuel originated from biomass. However, traditional liquid biodiesel catalyst generates a huge amount of waste water in the final purification procedure.

A new class of solid catalyst is developed by precise surface chemistry engineering to catalyze the biodiesel production. With excellent adaptability to low grade unrefined feedstock like waste cooking oil, the catalyst can provide complete solution to the waste water problem.
In addition, it operates at a significant lower temperature and pressure as compared with the existing solid biodiesel catalyst due to its high catalytic activity, which can reduce the energy and cost required for biodiesel production.
Special Features and Advantages:
One-step biodiesel production from low grade unrefined feedstock
No washing with fresh water required for biodiesel produced
Operates at low temperature and pressure which can reduce the cost
The catalyst demonstrates excellent reusability and robustness
Applications:
This new catalyst is designed for one-step energy saving biodiesel synthesis from low grade unrefined feedstock containing high free fatty acid and water content with no post-production washing required. Toxic methanol used can also be replaced by ethanol or propanol which makes the process more sustainable.