yeast
Gaetano T. Montelione Laboratory
CABM Protein NMR Laboratory

About the Lab

Layout for NMR Room Air System

Proposed Layout
for NMR Room Air System

 
 

Varian recommends Compressed Air supply with a dew point of -40 deg. F at the stipulated air pressures and flow rates shown in the table below. The designed capacity of the system shown above is expected to, more than exceed these requirements.

VARIAN STIPULATED AIR PRESSURE VALUES

CONDITION REQUIRED PRESSURE FLOW RATE (per instrument)
For the 600 MHz, four channel instrument 
- sample float and spin, probe/shim cooling and VT
45 psig   57 SCFH / 0.95 SCFM
- during sample eject 45 psig  102 SCFH / 1.7 SCFM
If system gets upgraded to accomodate CP/MAS 90 psig  170 SCFH / 2.83 SCFM

SCFM : Standard Cubic Feet per Minute
SCFH : Standard Cubic Feet per Hour

The following TABLE provides details of the various parts identified in the diagram above.

  • Brief principle of operation of the above system is given after the following table.
PART NO. DESCRIPTION MANUFACTURER/
MODEL NO.
DIMENSIONS
(inches)
L/W/H
WEIGHT (lbs.) OUTLET INLET COUPLING ELECTRICAL REMARKS
1. Backup Air Compressor SPEEDAIRE/4ME98
  23/31/71     350      3/4 " 208VAC/--A/ 3 phase 15.8 SCFM @ 90 PSI. 60 GAL. tank
with regulator and
safety valve.
2. Filter BALSTON/100-12-DX
   9/4/4    5      1/2 " N/A 93%
Oil/Particulate
Filtration
3. Filter BALSTON/100-12-BX   9/4/4     5     1/2 " N/A 99.99%
Oil/Particulate
Filtration
4. OR Gate FESTO/AirLogic Pressure
Dependent Valve 10413
  2/3/1       1/4 " -- 1170 Liters Per
Minute/Working
Pressure 1-10 bar
5. Filter HANKISON/HF7-16-4-
GL
   12/5/5   7      1/2 " N/A  General Purpose
 Air Line Fliter
6. Regenerative
Dessicant Air Dryer
HANKISON/DHW-10 30.5/22.9/6.75  135      1/2 " 115VAC/1phase -40 F Dew Point
@ 100 PSI In
Flow max: 10
SCFM Out Flow
max:8 SCFM
7. Filter HANKISON/HF5-16-4-
DGL
  12/5/5   7      1/2 " N/A High Efficiency
Oil Removal Filter
8. Air Storage Tank SPEEDAIR/-- 41/16/31 (dia)   125     1/2 " N/A 30 Gallons Size
200 PSA working
pressure
9. Refrigerated
Compressed Air
Dryer
INGERSOLL-/
RAND/SDR7
12.5/12.5/15.8   44     3/8 " 115VAC 1Phase +35F Dew Point
@ 100 Flow
max:7SCFM
10. VALVES V1-V10 DYNAQUIP/
VMH2.A9(1/2)/
              --   0.6 ea.      1/2 " N/A 600 PSI WOG/
150 PSI WSP
ratings

PRINCIPLE OF OPERATION

In the primary configuration for use:

  • valve V1 --> Open
  • valve V2 --> Closed
  • valve V3 --> Open
  • valve V4 --> Open
  • valve V5 --> Closed
  • valve V6 --> Closed
  • valve V7 --> Open


  • valve V8 --> Closed


  • valve V9 --> Closed


  • The diagram above is shown in primary configuration

During normal operation the NMR air supply is set in the primary configuration. CABM compressed air or the back-up compressor [1] generates pressurized air which enters the regenerative air dryer [6]. Dried air flows out of the dryer through the oil removal filter [7] and fills up the storage tank [8]. Air from the storage tank flows through valve V10 into NMR room 020B.


When there is a problem with the CABM Compressed Air:

    The use of an OR gate allows uninterrupted compressed air to the NMR system in the event of a degradation of CABM compressed air. The OR gate accepts inputs from the back-up compressor and CABM compressed air. The input with the higher pressure will be selected as the output by the OR gate.


When we need dry Nitrogen Gas supply instead of dried Air:                        

  • valve V3 --> Closed
  • valve V4 --> Closed
  • valve V7 --> Closed
  • valve V8 --> Open