FORM 2
THE PATENT ACT 1970
&
The Patents Rules, 2003
PROVISIONAL / COMPLETE SPECIFICATION
(See section 10 and rule 13)

1. TITLE OF THE INVENTION:
"Diffuser nozzle and Filter plate in cabin heater core assembly"
2. APPLICANT
(a) NAME: TATA TOYO Radiator Ltd
(b) NATIONALITY: Indian Company registered under the provisions of The Companies Act, 1956
(c) ADDRESS: Survey No. 235/245, Village Hinjewadi, Taluka Mulshi, Dist. Pune 411 027, M.S. India
3. PRREAMBLE TO THE DESCRIPTION
PROVISIONAL COMPLETE
The following specification describes the The following specification-
invention. particularly descpbelfthe invention and the majjnefm which it is to be pelformed.

Technical Field:
The present invention is related to an implementation of Diffuser nozzle and filter plate in Cabin heater core of Heating, Ventilating and Air conditioning system (HVAC hereinafter). More particularly, it is related to diffuser nozzle to diffuse the coolant flow and filter plate to filter out the slurry and metal swarf from engine carried by the coolant before passing through series of tubes in the core.
Background & Prior Art:
In contemporary and earlier heater cores, no diffuser and filter plate were observed.
Drawbacks in Prior Art:
As stated in the Prior art, in earlier heater cores, no diffuser were introduced. This results in very high entry velocity coolant, which leads to the higher turbulence resulting into higher drop in coolant pressure across top tank. Following drawbacks are observed:
1. Erosion and pitting corrosion at header plate and series of tubes.
2. Higher warranty failure rate due to erosion and corrosion due to metal swarf.
3. Chocking of heater core rubes due to deposition of slurry and metal swarf which is carried along with coolant from engine cooling jacket affecting the heat transfer efficiency of the heater core.
4. Excessive coolant pressure drop leads to cavitation and coolant pump life is reduced.
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Objects of Invention:
The main object of the present invention is to introduce a diffuser nozzle to diffuse the coolant flow and filter plate to filter out the slurry and unwanted objects before passing through series of tubes in heater core.
Another object of the present invention is to reduce or nullify the chocking of heater core tubes due to deposition of slurry which brings along with coolant from engine cooling jacket.
Yet another object of the present invention is to reduce erosion, cavitation and pitting at header plate and series of tubes.
One more object of the present invention is to increase the efficiency of coolant pump.
Brief Description of the Drawings:
Figure 1 is a heater core which is used in an automotive HVAC system. Figure 2 shows the functioning of HVAC system of automotive vehicle. Figure 3 shows assembly of the filter plate in the system. Figure 4 shows the filter plate.
Detailed Description of Invention:
The invention is illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures.
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As shown in figure 1, heater core is a U-pass type heat exchanger. A diffuser nozzle (2) and filter plate (11) are introduced in Heater core assembly. A diffuser nozzle (2) is assembled at the end of coolant inlet pipe (1) to heater core inlet tank (3a) to diffuse the coolant flow. By diffusing the coolant flow, coolant velocity decreases so impact of flow on tube (6) & header plate (8) retards and due to flow diversion all across the header plate (8) section, which leads to decrease in pressure drop in inlet section. Whereas filter plate (11) is assembled between coolant inlet flow opening and header plate (8) at coolant inlet inside heater core top tank (3a) to filter out the slurry and unwanted objects before passing through series of tubes (6). This is proposed to prevent the erosion of header plate (8) by avoiding pitting of slurry and also chocking of series of tubes.
As shown in Figure 2, coolant circulates among internal combustion engine (IC Engine) water jacket (13) to heater core through coolant pump (20). This pump runs by means of IC engine shaft. The engine coolant pump is designed by calculating certain pressure drop across the heater core, if the pressure drop in heater core is more than the designed; it leads to reduction in coolant pump efficiency. The coolant pump gets stressed due to higher pressure drop and fails early. One more cause of coolant pump failure is due to cavitation. This coolant pump design is major consideration in engine cooling system.
In any heat exchanger system, coolant pressure drops across tanks (3a, 3b, 7) and core (12). Hence to lower the scope of pressure drop across inlet tank (3a), diffuser nozzle (2) is assembled at the end of coolant inlet pipe (1) to tank (3a) as shown in Figure 3. Diffuser nozzle (2) diffuses the inlet flow velocity so that the recirculation (turbulence) intensity reduces and also
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lowers the intensity of jet force. Due to lower intensity of turbulence, pressure drop across inlet tank (3a) is retarded and due to lower flow jet intensity, excessive jet impact on tubes is avoided. Hence using diffuser nozzle, excessive pressure drop across inlet tank (3a) and rate of erosion on header plate (8) and series of tubes (6) are controlled. A diffuser nozzle (2) is made up of extruded tube of aluminum AA3003 material.
A filter plate (11) made of Aluminum AA3003 is assembled inside inlet tank (3a) between coolant inlet pipe (1) opening and series of tubes (6) entrance as shown in Figure 3. Major function of filter plate (11) is to filter out the slurry which is brought inside along with coolant flow from engine water jacket. The filtering mechanism avoids direct pitting on header plate (8) & series of tubes (6) and chocking of tubes as well. Direct pitting of slurry particles on header plate (8) & tubes (6) generates the erosion and pitting corrosion. Due to chocking of tubes (6), slurry obstructs the coolant flow which results into excessive pressure drop and influences heat exchange capacity as well. By implementing filter plate (11) in heater core assembly, the above said problems are almost eliminated.
Advantages of present invention:
The advantages of the present invention are mentioned below: i. Diffuser nozzle (2):
a) It provides proper coolant flow distribution to lower the turbulence intensity which causes excessive pressure drop across inlet tank (3a).
b) By lowering coolant side pressure drop, coolant pumping power is proposed to be conserved.
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c) It lowers coolant jet intensity over header plate & tubes; hence rate of erosion and cavitations is proposed to be controlled.
d) It eliminates cause of cavitation and thereby enhances the pump life and prevents early failure of heater core.
ii. Filter plate (11):
a) It filters out the slurry from inlet coolant flow to prevent pitting on header plate and also chocking of tubes.
b) It reduces the scope of pitting slurry particle on header plate & tubes which helps to prevent pitting corrosion and erosion.
c) It prevents chocking of tubes; hence heat transfer capacity of the heater core is maintained.
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Since all the parts in coolant flow path are made of Aluminum, they are compatible with each other and can be made in one-shot brazing process.