Pitot heat pump

A pitot heat pump is described wherein a multi-stage pitot pump is employed as the compression means in a heat pump thermodynamic cycle. The heat pump is comprised of a multi-stage vapor pitot pump, liquid pitot pump, turbine, vaporizer, evaporator, condenser and expansion valve. The turbine is used to rotate a shaft to which the impellers of the pitot pump are attached. Refrigerant gas from the evaporator enters the first stage of the pitot pump and the impeller therein forces the refrigerant gas outwardly where it enters the narrow end of a pitot tube provided therein. The discharge end of the pitot tube is in communication with the next stage of the pitot pump. In passing through the pitot tube, the refrigerant gas expands and the centrifugal force and the kinetic energy of the gas provide the energy whereby the refrigerant gas is compressed. After the last stage, the compressed gas is transmitted to the condenser of the heat pump.

BACKGROUND OF THE INVENTION 
This invention relates to a pitot pump and more particularly to a pitot 
pump which is ideally suited as the compression means in a heat pump 
thermodynamic cycle. 
In most heat pumps, the compression means is of the reciprocating type. The 
use of a pitot as a pump in a heat pump environment offers several 
advantages when applied to the heat pump, the primary advantage being that 
of simplicity. A heat pump employing a single moving part which rotates at 
a high speed enjoys simplicity and low cost provided the rotating part is 
inexpensive of manufacture. The advantages of a gas-fired pitot pump 
suitable for home application are simplicity, compactness and cost. A 
gas-fired heat pump of the type described also permits the realization of 
performance many times better than currently realizable with conventional 
gas-fired equipment. 
In the pitot pump of this invention, the fluid is imparted an angular 
momentum by a rotating element similar to an impeller and the resultant 
kinetic energy is transformed to pressure energy as the fluid passes 
through a diffuser-pick-off tube or pitot tube. The pressure developed in 
the pitot tube is ascertainable by conventional centrigual compression 
equations. 
Therefore, it is a principal object of the invention to provide a pitot 
pump. 
A still further object of the invention is to provide a pitot pump for use 
as the compression means in the thermodynamic cycle of a heat pump. 
A still further object of the invention is to provide a pitot heat pump. 
A still further object of the invention is to provide a pitot heat pump 
which is compact, simple and inexpensive. 
A further object of the invention is to provide a pitot heat pump which is 
extremely efficient. 
A still further object of the invention is to provide a pitot pump 
employing a plurality of stages which cooperate with each other to 
compress the refrigerant gas as it passes therethrough. 
These and other objects will be apparent to those skilled in the art.

SUMMARY OF THE INVENTION 
In the particular embodiment disclosed herein, a five-stage pitot pump is 
employed as the compression means in a heat pump thermodynamic cycle. The 
heat pump is comprised of the five-stage pitot pump, liquid pitot pump, 
turbine, vaporizer, evaporator, condenser and expansion valve. Preferably, 
the turbine is gas-fired and rotates a shaft to which the impellers of the 
five-stage pitot pump are attached. Refrigerant gas from the evaporator 
enters the first stage of the pitot pump and the impeller therein forces 
the refrigerant gas outwardly to force the refrigerant gas through the 
narrow end of a pitot tube provided therein. The discharge end of the 
pitot tube in each of the stages is in communication with the next stage 
of the pitot pump. The refrigerant gas expands as it passes through the 
pitot tube and the centrifugal force and the kinetic energy of the 
refrigerant gas provide the energy whereby the refrigerant gas is 
compressed. After the last stage, the compressed gas is transmitted to the 
condenser of the heat pump. 
DESCRIPTION OF THE PREFERRED EMBODIMENT 
The pitot pump of this invention is referred to generally by the reference 
numeral 10 and is ideally suited for use with conventional heat pump 
components including evaporator 12, condenser 14 and expansion valve 16. 
The evaporator, condenser and expansion valve are conventional in design 
and would include the necessary controls common to heat pumps generally 
available. The pitot pump 10 provides the compression means in the heat 
pump thermodynamic cycle, whether the heat pump is being used to heat or 
cool. The conventional reversal means for either heating or cooling 
operations is not depicted in the drawings. 
The numeral 18 refers to a gas-fired vaporizer having an outlet line or 
conduit 20 extending therefrom to turbine 22 including a rotatable shaft 
24 extending downwardly through the pitot pump 10. The vaporizer 18 
supplies the driving medium to the turbine to cause shaft 24 to be 
rotated. The discharge of the turbine 22 is connected to condenser 14 by 
conduit 26. As seen in FIG. 1, the discharge or outlet side of the 
evaporator 12 is connected to pitot pump 10 by conduit 28. The outlet of 
expansion valve 16 is connected to the inlet of evaporator 12 by conduit 
30. The discharge or outlet of the pitot pump 10 is connected to the inlet 
of condenser 14 by conduit 32. The numeral 34 refers to a single stage 
liquid pitot pump which is driven by the shaft 24 so that the fluid in 
compartment 36 is drawn upwardly thereinto and is pumped through the 
conduit 38 which is in communication with conduit 40 which extends to 
vaporizer 18 and to conduit 42 which extends to the inlet of expansion 
valve 16. 
The heat pump 10 described in the drawings is shown to have five identical 
stages located in compartments 44, 46, 48, 50 and 52. The interior of 
turbine 22 is sealed from compartment 44 by means of a gas-film bearing 
54. Likewise, the various compartments of the pitot pump are also 
hermetically sealed from each other by means of gas-film bearings 56 
and/or labryhth seals. 
Located within each compartment is a cup-like impeller 58 which is secured 
to the shaft 24 for rotation therewith. At least one pitot tube 60 is 
positioned within each of the compartments and has its inlet end 62 
closely positioned to the interior wall surface of the impeller 58 as best 
illustrated in FIG. 4. If desired, several pitot tubes 60 may be 
positioned within each of the stages. The outlet or discharge end of the 
pitot tube 60 in compartment 44 is in communication with compartment 46 as 
best illustrated in FIG. 2. As seen in FIG. 2, the outlets of each of the 
pitot tubes are in communication with the next stage with the discharge or 
outlet end of the pitot tube in compartment 52 being in operative fluid 
communication with the conduit 32. 
In operation, the gas-fired vaporizer 18 supplies the working medium to the 
turbine 22 to cause the rotation of shaft 24 preferably on the order of 
50,000 rpm. Refrigerant gas such as R-21 is supplied from the evaporator 
to compartment 44 by means of the conduit 28. The gas entering compartment 
44 is imparted angular momentum by the rotating impeller 58 and the 
kinetic energy thereof is transformed to pressure energy in the pitot tube 
60. As stated, the impeller 58 forces the refrigerant gas outwardly to the 
interior wall surface of the impeller where it enters the narrow end of 
the pitot tube and is subsequently conveyed to the next stage therebelow. 
The refrigerant gas is additionally compressed as it passes through the 
pitot tube 60. Thus the refrigerant gas is successively compressed in the 
compartments 44, 46, 48, 50 and 52 from approximately 5 to 100 pounds per 
square inch. 
After the gas has been compressed in the five stages of the pitot pump, the 
gas is supplied to the condenser 14 by means of the conduit 32. As 
previously stated, the pitot pump or liquid pump 34 is also operated by 
the shaft 24. Freon or refrigerant gas from the condenser 14 flows there 
into by means of the conduit 64 and is sucked upwardly into the impeller 
and into the pitot tube therein by the rotating impeller. The Freon is 
pressurized from approximately 100 psi to 1,000 psi and flows to the 
expansion valve 16 and thence to the evaporator. Part of the fluid from 
the pump 34 is also supplied to the vaporizer 18. 
Thus it can be seen that a novel pitot pump has been described for use in a 
heat pump which is compact, simple, inexpensive and efficient. It can be 
seen that the invention accomplishes at least all of the stated 
objectives.