10
CHAPTER 1: INTRODUCTION
087-0067 REV A
SCOTT SAFETY
Theory of Operation
This section covers the theory of operations of the system.
The purpose of the Air Breathing System is to produce breathing air that meets Grade
D/E of the CGA breathing air standard G-71 and National Fire Protection Association
(NFPA) 1989. The production of high-pressure breathing air can be divided into four
(4) categories:
•
Compression - Air compression is accomplished using a multi-stage compressor
assembly. This is performed by the Compressor unit.
•
Purification - Air purification is accomplished by using a mechanical filtration and
chemical purification process. This is performed by the Compressor unit.
•
Storage - Compressed and purified air is stored in ASME cylinders for use later.
This is performed by the Storage unit.
•
Charging - Compressed and purified air is filled into breathing air cylinders. This
is performed by the Charge Station unit.
– The Compressor's role: The compressor, takes in ambient air that is filtered and
then compressed in five stages. Each stage is equipped with a standard safety
value, set slightly above the normal working pressure of that stage. The value
releases high pressure air to protect the system in case of mechanical failure.
These pressures are displayed, depending on the model, on the analog gauges
or virtual gauges on the HMI. Moisture separators continuously remove
moisture from the compressor intercooler and after-cooler air circuits. The
condensate container collects the moisture from the moisture separators. The
container is drained as needed. When the discharge pressure reaches the
maximum preset level, the compressor is unloaded. After the pressurized air
leaves the compressor, it passes through a multi-stage purification system. The
number of stages depends on the horse power, and therefore the air output
capacity of the compressor. The higher the air output, the more purification
elements are needed. The purification system further dries the air and removes
other impurities. From the purification system, the air can go directly to
charging breathing air cylinders, or can be sent to high pressure storage
cylinders and maintain the pressure in the storage for charging several
breathing air cylinders before the compressor restarts to refill the storage.
– The Storage Unit’s role: Once the breathing air is compressed and purified, it
may be sent to high pressure storage cylinders and maintain the pressure in the
storage for charging several breathing air cylinders before the compressor
restarts to refill the storage. The storage may be up to four (4) ASME vertical
cylinders.
– The Charge Station’s role: Once the breathing air is compressed and purified, it
may be filled directly into breathing air cylinders using the charge station. The
charge station allows the simultaneous filling of two (2) cylinders while two (2)
additional cylinders can be attached and made ready on the outside of the
chamber.
Summary of Contents for HushAir Connect 7500
Page 1: ...User Guide 087 0067 Rev A HushAir Connect 7500 COMPRESSOR SYSTEM ...
Page 2: ......
Page 3: ...HushAir Connect 7500 User Guide COMPRESSOR SYSTEM 087 0067 Rev A ...
Page 8: ...IV CONTENTS 087 0067 REV A SCOTT SAFETY ...
Page 12: ...X LIST OF TABLES 087 0067 REV A SCOTT SAFETY ...
Page 42: ...20 CHAPTER 2 INSTALLATION 087 0067 REV A SCOTT SAFETY ...
Page 73: ...Configuring the System 51 SCOTT SAFETY 087 0067 REV A Figure 27 Override Status Screen ...
Page 106: ...84 CHAPTER 5 MAINTENANCE 087 0067 REV A SCOTT SAFETY Figure 48 Oil Drain Location 3 1 2 ...
Page 112: ...90 APPENDIX A SPECIFICATIONS 087 0067 REV A SCOTT SAFETY ...
Page 119: ......
