AU427999B2 - Improved air conditioning unit - Google Patents

Description

THIS INVENTION relates G,3 2 1/71 an improved air conditioning air conditiorin unit for use in very dusty atmospheres.

In mining operations in areas such as the North West of

Western Australia, where high temperatures are encountered

it is very desirable that the operator's compartment or

cabin on the various items of equipment be air conditioned

to maintain reasonable working conditions. Cpnventional air conditioning units are not sufficiently robust for

use in such situations and also because of the extremely

dusty conditions, they rapidly become clogged with dust

and ineffective. The object of the present invention is to provide anair conditioning unit which is particu-

larly suitable for use in such circumstances.

The present invention therefore resides in an air

conditioningunit wherein external air is passed through a

dust separating unit such as a cyclone and part of the

dust-free air is used for cooling the condenser of the

unit and part is fed into the space to be conditioned

to maintain it at a positive pressure above atmospheric

pressure to exclude dust from the space.

More particularly, the invention resides in an air condi-

tioning unit comprising a compressor, a condenser coil,

an evaporator coil, a substantially air tight chamber,

dust separating means and fan means for drawing atmospher-

ic air into the chamber through the dust separating means

and for discharging substantially dust-free air from

the chamber through the condenser coil to atmosphere

and through the evaporator coil to the space to be con-

ditioned and for maintaining said chamber and said space

at a positive pressure above atmospheric pressure. 427 99&

3 6,3 2 1/7 The invention will be better understood by reference

to the following description of one specific embodiment

thereof shown in the accompanying drawings wherein:-

3 6,32 1171 Fig. 1 is a plan view;

Fig. -2 is a section on line 2-2 of Fig. 1; and Fig. 3 is a section on line 3-3 of Fig. 1.

In the embodiment shown in the drawings the majority

of the components are mounted in a high side casing 11

whilst the balance of the components are mounted in a low side casing 12. The high side casing is located

externally of the space to be air conditioned such as the operator's cabin of some unit of mining equipment

with the low side casing projecting into said cabin.

Preferably the cabin has suitable insulation and all

openings provided with suitable seals to render it sub-

stantially air tight although some leakages can be tol-

erated. The high side casing 11 forms a plenum chamber

having an inlet 13 and outlet 14. A cyclone separator comprising a bank of small cyclones 16 is fitted to

the inlet in a substantially air tight manner whilst a

condenser coil 17 is mounted in one wall of the casing

11. A compressor 18 and a liquid refrigerant tank 19

are mounted within the casing as is an electric motor

having its shaft projecting from both ends. One end of the shaft of the motor 20 is coupled to a large

capacity centrifugal fan 21 whilst the other end of the

shaft projects into the low side of the casing and is

coupled to a small radial type fan 22. An evaporator 4 coil 23 is positioned within the low side casing 12

4 427999

36,32 1171 The The outlet registers 24. is provided with air ich casing slopes down- .oor or bottom 25 of the low side is fitted at evaporator coil and rdly away from the 26 for dis- with P trap drains ts lowermost position Air from the to the atmosphere. harging condensate the low side casing through lenum chamber passes to 28. The air control louvres small filter 27 and the high from the exterior of ilter 27 is accessible louvres purposes whilst the idecasing for cleaning air admitted the amount of fresh 28are used to control with rettrn where it is mixed tothe low side casing being blown the opening 29 before air drawn through coil 23. through the evaporator coil the using clean air for cooling the evaporator By by maintain- clogged with dust and coil does not become positive and the space at a ing the plenum chamber space. from entering the pressure dust is prevented is the ambient air temperature In conditions where not required, the refrigeration such that cooling is and the fan system may be omitted components of the clean fresh air tLLd hm- r used for supplying

to the space to be conditioned.

Claims (1)

1. 36132 1iP-1 The claims defining the invention are as follows:

   1. An air conditioning unit comprising a compressor, a condenser coil, an evaporator coil, a substantially air tight chamber, dust separating means and fan means for drawing atmospheric air into the chamber through the dust separating means and for discharging sukbstan- tially dust free air from the chamber through the con- denser coil to atmosphere and through the evaporator coil to the space to be conditioned and for maintaining said chamber and said space at a positive pressure above atmospheric pressure.

   2. An air conditioning unit as claimed in claim 1, wherein the dust separating means comprises a bank of small cyclones.'

   3. An air conditioning unit as ca edin claim 1 or 2, wherein the compressor and a liqi.~ k~associated therewith are mounted in a high aide casing which forms the chamber,. the condenser coil is mounted in one wall of the high side casing, the evaporator coil is mounted in a low side casing projecting into the space to be conditioned said dust separating means are located ad- jacent an inlet to said high side casing said fan means comprise a large capacity centrifugal fan located ad- jacent said inlet and a small radial type fan located behind said evaporator coil, said high side casing be- ing provided with an outlet through which air can pass to said low side casing and said low side casing being provided with one or more air outlet registers.

   a 427999

   3 6,32 1/7i 4. An air conditioning unit as claimed in claim .3 wherein said outlet is provided with a small filter and air control louvres.

   An air conditioning unit wherein'external air is passed through a dust separating unit.such as a cyclone and part of the dust free air is used for cooling the condenser of the unit and part is fed into the space to be conditioned to maintain it at a positive pressure above atmospheric pressure to exclude dust from the space.

   6. An air conditioning unit substantially as herein described and as shown in the accompanying drawings.

   DATED this Twentyfifth day of November, 1971.

   ACME ENGINEERING PTY, LTD.

   Applicant

   R.C. WRAY ASSOCIATES, Perth, Western Australia, Patent Attorney for Applicant.

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