Prochem Legend GT - Manual (Page 30)

28
Operations
Always wear hearing protection and proper
personal protection equipment when operating
unit.
Water Pumping and Heat Transfer System
Cold water enters the console through the water inlet.
When the water box is full the valve will automatically
shut off.
Water then flows from the water box, through the
strainer, into the solution pump. The water is pumped to
the pressure regulator manifold, which provides and
maintains the desired pressure setting.
The pressure regulator manifold includes a pulse hose,
which helps reduce pressure spikes from the pump.
A certain amount of water is by-passed from the
pressure regulator due to over pumping capacity of the
solution pump. Water that is not called for in the
cleaning process is channeled through a copper heater
core in the front of the heat exchanger box. This bypass
water circulates several times through the heater core
pre-warming the water.
The gases coming from the vacuum pump and the
engine exhaust are forced through the middle and rear
heater core creating the hottest area of the heat
exchanger box, and increasing the heat transfer to the
circulating water.
The hot water passes to the solution outlet manifold
where cleaning chemicals are injected from the
chemical pulse pump. This manifold serves as a
connecting point for the high-pressure hoses. Also a
check valve is located in this outlet manifold prohibiting
chemicals from backing up into the system.
The cleaning solution then passes through high-
pressure solution hoses and is distributed by the
cleaning tool to a surface that is being cleaned,
completing the water pumping and heating cycle of the
cleaning unit.
Heat Exchanger
The water temperature in the plumbing system is raised
for better cleaning. This happens in the heat
exchanger. The heat exchanger is made up of three
stages. These three stages are engine exhaust stage,
the mixing stage, and the pre-warming stage.
The angled rear heat exchanger core receives its heat
only from the engine exhaust gases. This core
becomes extremely hot and should not be touched
while the machine is in operation. Allow the machine to
cool down completely before attempting to service this
area.
The middle core receives its heat from the mixing of
both the engine exhaust and the vacuum pump
exhaust. The vacuum pump heats incoming air as it is
compressed. This hot air is mixed with the hot engine
exhaust gases exiting the angled rear core. This
mixture of hot air and gases is then forced through the
middle core and on through the front heat exchanger
core.
The front core continues to extract heat from the mixed
gases; but, this heat is used to pre-heat the water box
as a preliminary hot water reservoir.
86313050 LEGEND GT