**2.4 Gasket material**

In plate heat exchangers it is the limit factor contour. Therefore, it is very important to choose the 'right' gasket material. Various sealing types according to application are listed below. One of the most important points that should not be forgotten is that the exchanger gaskets are produced in three qualities, normal, sulfur and peroxide. These three quality seal materials are peroxidized when compared with each other, and the material always ensures the best performance in terms of operating conditions [4, 5].

#### **2.5 Plate geometries used in plate heat exchangers**

Almost all plates used today are of the fishermen type. Traditionally, fish hatch plates are now made with two arrows, one is the "high-theta" with high resistance to flow and the other is the "low-theta" with low resistance against flow.

These two types of plates can be combined in three different ways, each with different characteristics in terms of heat transfer and pressure drop.

The symmetrical plates and the primary and secondary sides are geometrically identical and the plate deck can best be used on only one side. A later innovation is the asymmetrical plaque, these two teams have arrows, one high-theta and the other low-theta. Plates having different plate geometries are given in **Figures 2**–**6**

These two plates can be combined in the form of six different flow channels, each with different heat transfer characteristics. Gasket materials commonly used in plate heat exchangers are given **Table 2**.

The asymmetric plates also provide asymmetrical plate deck formation, where the geometry of the primary side is different from the geometry of the secondary side. These two aspects can be used separately in the best way, thus reducing the required heat transfer surface and providing better utilization of the existing pressure reduction.

Plates are manufactured in different thicknesses up to 8 mm by 0.4 mm in accordance with the designed pressure rating and maintenance stability. Thin plates are not used in cleaning applications and other applications where the unit needs to be opened. The most commonly used materials in geothermal applications are AISI 316, 254 SMO and commercial pure (grade 1) titanium. Other high alloy materials are also used where geothermal fluids are very corrosive.

**233**

**Figure 5.**

**Figure 4.**

*Asymmetrical high and low-theta plates.*

*Plate Heat Exchangers: Artificial Neural Networks for Their Design*

*DOI: http://dx.doi.org/10.5772/intechopen.95376*

*Three different channels by combining two symmetrical plates.*

*Six different flow channels combined from two different platters.*

**Figure 2.**

**Figure 3.**

*Two arrowhead chevron plates.*

*Plate Heat Exchangers: Artificial Neural Networks for Their Design DOI: http://dx.doi.org/10.5772/intechopen.95376*

**Figure 2.** *Two arrowhead chevron plates.*

*Heat Transfer - Design, Experimentation and Applications*

**2.4 Gasket material**

operating conditions [4, 5].

**2.5 Plate geometries used in plate heat exchangers**

in plate heat exchangers are given **Table 2**.

are also used where geothermal fluids are very corrosive.

PHEXs are produced from different materials in today. These alternative materials are aluminum, carbon steel, stainless steel, nickel alloys, zirconium and titanium. For many chemical processes, Zirconium is a cost-effective material of construction in shielding process equipment systems from destructive corrosive leaks. With incredibly high resistance to corrosion, Zirconium HEXs can withstand some of the harshest situations. This translates to decreased maintenance expense, with downtime kept to a minimum. Copper has many preferred specifications for thermally efficient and durable HEXs. Above all else, copper is an perfect conductor of heat. This means that copper's high thermal conductivity allows heat to pass through it speedly. Other required specifications of copper in HEXs include its corrosion resistance, biofouling resistance, maximum allowable stress and internal pressure, creep rupture strength, fatigue strength, hardness, thermal expansion, specific heat, antimicrobial specifications, yield strength, high melting point, ease of fabrication, and ease of joining. In chemical processes, the use of titanium HEXs has been found to be a costeffective method of resisting leaks from corrosion on a process line. Titanium HEXs has superior corrosion resistance, high heat transfer efficiency, non-breaking

property and provide an extended service life compared to other materials.

In plate heat exchangers it is the limit factor contour. Therefore, it is very important to choose the 'right' gasket material. Various sealing types according to application are listed below. One of the most important points that should not be forgotten is that the exchanger gaskets are produced in three qualities, normal, sulfur and peroxide. These three quality seal materials are peroxidized when compared with each other, and the material always ensures the best performance in terms of

Almost all plates used today are of the fishermen type. Traditionally, fish hatch plates are now made with two arrows, one is the "high-theta" with high resistance to

These two types of plates can be combined in three different ways, each with dif-

The symmetrical plates and the primary and secondary sides are geometrically identical and the plate deck can best be used on only one side. A later innovation is the asymmetrical plaque, these two teams have arrows, one high-theta and the other

These two plates can be combined in the form of six different flow channels, each with different heat transfer characteristics. Gasket materials commonly used

Plates are manufactured in different thicknesses up to 8 mm by 0.4 mm in accordance with the designed pressure rating and maintenance stability. Thin plates are not used in cleaning applications and other applications where the unit needs to be opened. The most commonly used materials in geothermal applications are AISI 316, 254 SMO and commercial pure (grade 1) titanium. Other high alloy materials

The asymmetric plates also provide asymmetrical plate deck formation, where the geometry of the primary side is different from the geometry of the secondary side. These two aspects can be used separately in the best way, thus reducing the required heat transfer surface and providing better utilization of the existing

flow and the other is the "low-theta" with low resistance against flow.

low-theta. Plates having different plate geometries are given in **Figures 2**–**6**

ferent characteristics in terms of heat transfer and pressure drop.

**232**

pressure reduction.

**Figure 3.** *Three different channels by combining two symmetrical plates.*
