DESC:DETAILED DESCRIPTION
[0047] The following contents are a detailed description of the present invention. The description provided is sufficient in detail to enable those skilled in the art to practice the invention. However, the level of detail should not be construed as limiting, but rather as providing examples of the invention. It is understood that various modifications, equivalents, and alternatives falling within the scope of the appended claims may be made without departing from the spirit of the invention.

[0048] Unless the context requires otherwise, throughout the specification which follow, the word “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense that is as “including, but not limited to.”

[0049] The present invention discloses a Plate-Type Counter-Flow Evaporative Condenser [100], which provides a significantly improved, efficient, and structurally optimized heat exchange unit for condensing refrigerant vapours using a combination of evaporative cooling and air-induced flow mechanisms. The present invention eliminates the longstanding limitations of conventional tube-type counter-flow and cross-flow evaporative condensers. The invention is developed through a precise arrangement of engineered components, assembled in a vertical sequence beginning from the water tank base, progressing through the heat exchange zones, and terminating at the exhaust and airflow regulation zone at the top. This vertically modular construction ensures ease of assembly, access for maintenance, optimal airflow design, and reduced energy and water usage.

[0050] The invention offers a compact footprint, optimal energy utilization, and reduced maintenance requirements due to corrosion-resistant construction and easy-access servicing. The entire condenser structure is fabricated using SS-304 components to prevent rusting and minimize fouling. The structural frame is developed using SS-304 square tubes, designed and tested for vibration and wind load resistance.

[0051] Referring to Figure 1(a) and Figure 1(b), the structure of the proposed Plate-Type Counter-Flow Evaporative Condenser [100] begins at the bottom with the Water Tank Assembly [109]. This tank is constructed using SS-304 stainless steel and functions both as a reservoir and as a thermal component by facilitating secondary heat rejection. The tank is rectangular and includes provisions for a make-up water inlet, bleed-off outlet, and drain plug; wherein the Water Tank Assembly [109] is supported on an MS-painted structural base frame designed to carry vertical load and dynamic vibration from the condenser assembly.

[0052] Mounted directly above the Water Tank Assembly [109] is the Laser Welded Pillow Plate Bank Assembly [105], which is fastened to the Water Tank Assembly [109] support brackets and enclosed within a vertical stainless-steel frame. The pillow plates are created using CNC-guided laser welding on 1.2 mm thick SS-304 sheets. The welded sheets are then hydroformed to produce a turbulent internal channel profile that increases the heat transfer surface area and promotes turbulent refrigerant flow. The refrigerant enters through the Gas Inlet Header [113], flows through the plates, and exits via the Liquid Outlet Header [111]; wherein the header pipes are flanged to the plates and pressure tested to 25 bar. The plate bank frame is equipped with modular bolting connections using SS-304 fasteners to enable easy replacement of individual plates without dismantling the entire assembly.

[0053] As part of the modular design, a Desuperheater Coil [112] is integrated just before the refrigerant enters the Laser Welded Pillow Plate Bank Assembly [105]. The coil is constructed from SS-304 seamless tubing, bent into a U-loop pattern, and is connected via the Gas Inlet [113] and Liquid Outlet [114]. This arrangement is designed to reduce superheat, enhancing both the thermal efficiency and the lifespan of the primary plate bank. The coil is securely mounted on SS flats and thermally isolated from surrounding components to prevent premature heat dispersion. The Desuperheater Coil [112] is particularly effective in systems operating with high superheat refrigerants or under fluctuating load conditions, ensuring optimal performance under diverse operating environments. Notably, such a Desuperheater Coil [112] is absent in conventional evaporative condensers, which rely solely on direct condensation within the coil or plate bank. The integration of this additional pre-cooling stage not only improves condensation efficiency but also significantly enhances refrigerant stability and system responsiveness, making the present invention distinct and more effective than conventional and existing counter-flow or cross-flow condensers available in the market.

[0054] On the periphery of Section-C, the Air Inlet Louvers [107] are installed on all four vertical walls, supported by an outer frame welded to the condenser body. The louvers, fabricated from PVC or anodized aluminium, are slotted to allow uniform air intake while filtering dust and insects. These components ensure consistent bottom-to-top air movement across the evaporative zones. The louvers are modular and replaceable, fixed using SS-304 screws with gaskets to ensure no air leak and are UV-stabilized to avoid degradation.

[0055] Referring now to Figure 8, the Recirculation Pump [108] is bolted near the Water Tank Assembly [109] on a vibration-isolated skid. It is connected to a 2” SS-304 riser that supplies water to the Water Distribution System [104] mounted at the top. The pump is rated at 11.2 CMH and consumes 1.5 kW under operating head conditions; wherein the impeller is of closed-type SS construction and shaft-sealed with a mechanical graphite seal. The pump is mounted with anti-vibration pads and flexible coupling to avoid transmission of mechanical resonance to the main structure.

[0056] Continuing upward, Section-B houses the Honeycomb Fills [106], as shown in Figure 7. The fill blocks are made of structured PVC measuring 1824 mm x 300 mm x 300 mm and mounted in a staggered layout supported on SS-304 frames. Water from above flows downward through these fills, forming thin films and droplets that are cooled by ambient air flowing upward. This configuration promotes enhanced latent heat absorption from the water by the counter-flowing air stream. The fills are modular and are designed for slide-in-slide-out operation for ease of replacement and service.

[0057] Above the fills, the Water Distribution System [104] is installed, comprising eight 2.5” PVC laterals fitted with a total of 40 spray nozzles, each angled to ensure even coverage across the fill and plate zones. These laterals are supplied by a 3” SS-304 header, flanged and gasketed for leak-proof operation; wherein the nozzles produce cone-shaped sprays with droplet sizes between 1.5–2.5 mm for optimal surface coverage. The nozzles are threaded and can be easily replaced in case of clogging or wear.

[0058] At the topmost zone, Section-A as per Figure 6, the Drift Eliminator [103] and VFD Regulated Axial Fan [102] are mounted. The Drift Eliminator [103] comprises modular PVC units, each 1825 mm x 300 mm x 130 mm, held in SS-304 brackets and sealed with butyl rubber to avoid air bypass; wherein the Drift Eliminator [103] is mounted to the outer body of the A-Section with the help of the SS-304 x 1.5 mm Angles which are mounted to the main body using SS-304 Nut/Bolts and washers of M8 x 25 mm x 10 Nos. with Butyl Tape placed between the joints to ensure water and air tightness.

[0059] Above the Drift Eliminator [103] sits the VFD Regulated Axial Fan [102], delivering approximately 21,000 CMH airflow at 125 Pa pressure. The fan has PVC blades and an aluminium hub and is mounted on a 5 HP, 1540 RPM, 415V, 50Hz, IP-55 motor. The motor is connected via M6 x 50 mm SS-304 bolts and has a protective safety mesh and rain cover. The standard motor includes a terminal box, which is connected to the main terminal box using a 2.5 mm² x 4 core copper wire; wherein PG glands are used for sealing the cable entries and 6 mm cable lugs are provided for termination, ensuring a weather-resistant and safe electrical connection. A dedicated earthing line is also provided from the main terminal to the motor body.

[0060] The assembled Plate-Type Counter-Flow Evaporative Condenser [100] operates in a synchronized counter-flow mode. Ambient air enters through the Air Inlet Louvers [107] and rises through the Honeycomb Fills [106], where it interacts with the descending water and absorbs latent heat. However, due to the specific structural arrangement, the airflow path is designed to be separated from the water film that flows over the Laser Welded Pillow Plate Bank Assembly [105], ensuring that the water film remains undisturbed during its descent. Simultaneously, water sprayed from the Water Distribution System [104] travels downward through the fills and forms a stable, uninterrupted film over the outer surface of the Laser Welded Pillow Plate Bank Assembly [105], facilitating efficient heat exchange with the refrigerant circulating inside. The refrigerant condenses and exits through the Liquid Outlet [111], while the warmed water is collected in the Water Tank Assembly [109] and recirculated by the Recirculation Pump [108]. Moisture-laden air is captured by the Drift Eliminator [103] before being discharged by the VFD Regulated Axial Fan [102] through the Warm Air Outlet [101].
,CLAIMS:We Claim:
1. A Plate-Type Counter-Flow Evaporative Condenser [100] comprising of a vertically modular structure having three functional zones assembled sequentially from bottom to top, characterized in that the said Plate-Type Counter-Flow Evaporative Condenser [100] comprises:

- a Water Tank Assembly [109] positioned at the bottom configured to act as a hot water reservoir and structural support base;

- a Laser Welded Pillow Plate Bank Assembly [105] mounted directly above the said Water Tank Assembly [109], configured for refrigerant condensation;

- a Honeycomb Fill Section [106] disposed above the said Laser Welded Pillow Plate Bank Assembly [105] for air-water heat exchange;

- a Water Distribution System [104] arranged above the said Honeycomb Fill Section [106] for uniform water spraying;

- a Drift Eliminator [103] and a VFD Regulated Axial Fan Assembly [102] positioned at the topmost section, configured for air discharge and droplet capture;
wherein a counter-flow of refrigerant, water, and air is established through the sequential assembly of said components.

2. The Plate-Type Counter-Flow Evaporative Condenser [100] as claimed in Claim 1, wherein the said Water Tank Assembly [109] is fabricated using SS-304 Pillow Plates, includes make-up, bleed-off, and drain connections, and is configured to recirculate water through a Recirculation Pump [108] to the said Water Distribution System [104].

3. The Plate-Type Counter-Flow Evaporative Condenser [100] as claimed in Claim 1, wherein the said Laser Welded Pillow Plate Bank Assembly [105] comprises of hydro-formed SS-304 Pillow Plates fixed within a modular frame; characterized in that the Hot Refrigerant Gas [110] enters through a Gas Inlet Header [113], flows turbulently through the internal channels of the said Laser Welded Pillow Plate Bank Assembly [105], and exits as condensed liquid through a Liquid Outlet Header [111].

4. The Plate-Type Counter-Flow Evaporative Condenser [100] as claimed in Claim 1, wherein the Laser Welded Pillow Plate Bank Assembly [105] comprises a Desuperheater Coil [112] mounted upstream, characterized in that the said Desuperheater Coil [112] reduces refrigerant superheat, improving thermal efficiency and minimizing energy consumption, with the Gas Inlet [113] and Liquid Outlet [114] configured to regulate the refrigerant temperature before entry into the Laser Welded Pillow Plate Bank Assembly [105].

5. The Plate-Type Counter-Flow Evaporative Condenser [100] as claimed in Claim 1, wherein the said Honeycomb Fill Section [106] comprises a plurality of structured PVC fill blocks arranged in a grid layout, characterized in that the said Honeycomb Fill Section [106] is configured to pre-cool the sprayed water via contact with ambient air entering through Air Inlet Louvers [107].

6. The Plate-Type Counter-Flow Evaporative Condenser [100] as claimed in Claim 1, wherein the said Water Distribution System [104] comprises of a 3” SS-304 header pipe supplying eight 2.5” PVC laterals fitted with a plurality of spray nozzles, characterized in that the said Water Distribution System [104] is configured to ensure uniform water coverage over the said Honeycomb Fill Section [106] and the said Laser Welded Pillow Plate Bank Assembly [105].

7. The Plate-Type Counter-Flow Evaporative Condenser [100] as claimed in Claim 1, wherein the said Drift Eliminator [103] comprises of modular PVC eliminator blocks mounted with SS-304 brackets and sealed with butyl tape, characterized in that the said Drift Eliminator [103] is configured to capture entrained water droplets prior to air discharge.

8. The Plate-Type Counter-Flow Evaporative Condenser [100] as claimed in Claim 1, wherein the said VFD Regulated Axial Fan [102] comprises of PVC wings and an aluminium hub mounted on a 5 HP, 1540 RPM, 415V, 50Hz, IP-55 motor enclosed within a fan casing, characterized in that the said VFD Regulated Axial Fan [102] is configured to generate an induced draft airflow across the said Plate-Type Counter-Flow Evaporative Condenser [100].

9. The Plate-Type Counter-Flow Evaporative Condenser [100] as claimed in Claim 1, wherein the refrigerant flows through the said Laser Welded Pillow Plate Bank Assembly [105] in a direction opposite to the falling water, and the air flows upward in counter-flow to both, characterized in that this counter-flow arrangement significantly enhances thermal performance, improves condensation efficiency, and reduces scale formation, compared to conventional systems.

10. The Plate-Type Counter-Flow Evaporative Condenser [100] as claimed in Claim 1, wherein the assembly sequence begins with the installation of the said Water Tank Assembly [109], followed by the said Laser Welded Pillow Plate Bank Assembly [105], the said Honeycomb Fill Section [106], the said Water Distribution System [104], the said Drift Eliminator [103], and finally the said VFD Regulated Axial Fan [102]; characterized in that each component is modularly fixed using stainless steel fasteners and flanged joints.

11. The Plate-Type Counter-Flow Evaporative Condenser [100] as claimed in Claim 1, wherein the said condenser reduces water usage by up to 54%, and electrical energy consumption by up to 40%, characterized in that the specific counter-flow arrangement and modular design allow refrigerant condensation to occur at lower saturation temperatures under equivalent operating conditions, resulting in significant operational cost savings compared to conventional tube-type evaporative condensers.

12. The Plate-Type Counter-Flow Evaporative Condenser [100] as claimed in Claim 1, wherein the said electrical integration of the VFD Regulated Axial Fan [102] comprises a motor terminal box connected to the main terminal box using a 2.5 mm² × 4 core wire, PG glands, and 6 mm cable lugs, characterized in that the electrical system ensures secure, moisture-resistant operation under industrial conditions.

13. The Plate-Type Counter-Flow Evaporative Condenser [100] as claimed in Claim 1, wherein each of the said Honeycomb Fill Section [106], Water Distribution System [104], and Laser Welded Pillow Plate Bank Assembly [105] is modularly mounted and detachable, characterized in that the individual components are serviceable and replaceable without requiring dismantling of the entire Plate-Type Counter-Flow Evaporative Condenser [100].

14. The Plate-Type Counter-Flow Evaporative Condenser [100] as claimed in Claim 9, wherein the said structural configuration is characterized in that the air stream is isolated from directly contacting the water film flowing over the Laser Welded Pillow Plate Bank Assembly [105], thereby maintaining water film integrity and enhancing thermal performance.