Distributor

[Samarjit Sen]

We are executing a Cold Room project. One of my technicians has misplaced the nozzle of one distributor and has connected the TEV. Could some one tell me that in case the the nozzle of the distributor is not provided, what effect would it have on the operation and the performance of he plant.

At this stage to import the nozzle from the coil manufacturer is going to be time consuming and we have to commission the plant.

Please advise.

[Dan]

The position of the TEV and the quantity of tubes feeding the evaporator would matter. If the valve was feeding in an upright position, you might have some reasonable distribution. If the valve feeds horizontally, there will be a tendency to flood the lower circuits and starve the upper circuits.

I have seen supermarket cases operate surprisingly well without the orifice in the distributor. But these are coils with only 3 circuits and the accidental luck of feeding in an upright position.

[LRAC]

Hi Samarjit Sen

It might be worth checking the paperwork that came with the coil, some coils don't need the restrictor depending on what refrigerant your using. Take Frigobohn they always supply a restrictor but you only use it if using R22.

Kind regards
Lrac

[Samarjit Sen]

Thanks for the information. The Evaporators being used are from Heatcraft Larkin. I am happy to say that the nozzle has been located and installed. However during this short period I found out that it is important to have the nozzle of the distributor as it balances the flow of liquid and the vapour.

[US Iceman]

However during this short period I found out that it is important to have the nozzle of the distributor as it balances the flow of liquid and the vapour.

Exactly right. The pressure drop across the distributor is important, and the orifice plays a major role in this.

In the selection process for the TXV you have the following pressure drops which have to be accounted for to ensure good valve performance:

1. Pressure drop across the TXV
2. Pressure drop across the distributor (with the proper orifice)
3. Pressure drop across the distributor tubes

All three of these are used.

[Andy]

Thanks for the information. The Evaporators being used are from Heatcraft Larkin. I am happy to say that the nozzle has been located and installed. However during this short period I found out that it is important to have the nozzle of the distributor as it balances the flow of liquid and the vapour.

Heatcraft and Frigobohn are one and the same

Kind Regards Andy