Graphite Condenser
Heat Exchangers
Graphite Condenser
1. Product Overview
The graphite condenser is a specialized condensing heat exchanger that uses impregnated graphite as the heat-transfer element. Each unit is built around graphite blocks together with sealing elements, a shell (on enclosed-type models), inlet and outlet nozzles, and a support structure. Owing to the outstanding corrosion resistance and thermal conductivity of impregnated graphite, it condenses highly corrosive vapors reliably and efficiently.
Typical duties include condensation of hydrochloric acid gas, sulfuric acid mist, organic acid vapors and mixed-acid process streams, as well as condensation during pharmaceutical intermediate synthesis.
Key characteristics: excellent resistance to strong acids and oxidizing media (not suitable for strong alkalis or fluoride-containing media); a brittle graphite material that must be handled with care; available with falling-film absorption for combined condensation–absorption duty.
2. Working Principle
Corrosive vapor enters the graphite block through the gas passages and travels along the longitudinal channels, while the cooling medium flows countercurrently through the adjacent channels. On contacting the graphite channel walls, the vapor gives up its latent heat and condenses into a liquid film that runs down the walls and drains from the condensate outlet; the cooling water leaves the unit after absorbing the heat. Through the impregnated graphite matrix and the sealed construction between channels, the block isolates the corrosive media while transferring heat.
3. System Classification
By Structural Form
| Type | Features | Application |
|---|---|---|
| Round block type (3K type) | Cylindrical graphite blocks stacked vertically, sealed with PTFE gaskets between blocks | Most common, versatile, easy to maintain |
| Rectangular block type | Rectangular graphite blocks, sealed with gaskets between blocks | Custom shapes, specific installation space requirements |
| Shell-and-tube graphite type | Graphite tubes in a shell structure | Specific applications, fewer in condensation service |
By Process Function
| Type | Features | Application |
|---|---|---|
| Condensation only | Only condensation heat exchange | Simple condensation process |
| Condensation with falling-film absorption | Equipped with liquid distributor, absorption and condensation simultaneously | Condensation-absorption combined process (e.g., HCl absorption) |
| Condensation with gas-liquid separation | Equipped with gas-liquid separator at top | When non-condensable gas separation is needed |
4. Detailed Technical Parameters
4.1 Graphite Material Properties
| Item | Specification |
|---|---|
| Graphite type | Phenolic resin impregnated (most common) / Furan resin impregnated / PTFE impregnated |
| Thermal conductivity | 100～130 W/(m·K) |
| Service temperature | Phenolic: -20°C～170°C; Furan: -20°C～200°C; PTFE: -20°C～220°C |
| Corrosion resistance | Resistant to most strong acids (HCl, H2SO4, H3PO4, etc.), organic acids, organic solvents |
| Unsuitable media | Strong alkalis (NaOH, KOH), fluoride media (HF, fluorides), strong oxidizing media (conc. HNO3, conc. H2SO4 at high temp requires caution) |
| Density | Approx. 1.8 g/cm³ |
| Compressive strength | ≥60MPa |
| Tensile strength | ≥25MPa |
4.2 Typical Specification Table
| Heat Exchange Area (m²) | Block Dia. (mm) | No. of Blocks | Hole Dia. (mm) | No. of Holes | Cooling Water Nozzle | Gas Nozzle | Condensate Nozzle |
|---|---|---|---|---|---|---|---|
| 3～5 | Φ300～Φ400 | 3～5 | Φ12/Φ15/Φ18 | By area | DN25～DN32 | DN32～DN40 | DN20～DN25 |
| 5～10 | Φ400～Φ500 | 5～8 | Φ15/Φ18/Φ22 | By area | DN32～DN40 | DN40～DN50 | DN25～DN32 |
| 10～20 | Φ500～Φ600 | 8～15 | Φ18/Φ22/Φ25 | By area | DN40～DN50 | DN50～DN65 | DN32～DN40 |
| 20～40 | Φ600～Φ800 | 15～25 | Φ22/Φ25/Φ30 | By area | DN50～DN65 | DN65～DN80 | DN40～DN50 |
| 40～80 | Φ800～Φ1000 | 25～40 | Φ25/Φ30 | By area | DN65～DN80 | DN80～DN100 | DN50～DN65 |
| 80～150 | Φ1000～Φ1200 | 40～60 | Φ30 | By area | DN80～DN100 | DN100～DN150 | DN65～DN80 |
Note: actual configuration may vary with hole diameter and count, number of passes, falling-film absorption requirements, etc.; customization is available.
4.3 Design Conditions & Performance Indicators
| Parameter | Specification |
|---|---|
| Design pressure | Shell side: Atmospheric～0.4MPa; Hole side: Atmospheric～0.4MPa (varies by specification) |
| Design temperature | -20°C～200°C (depending on impregnation resin type) |
| Overall heat transfer coefficient (typical) | 150～800 W/(m²·K) (varies by media and conditions) |
| Sealing method | PTFE gasket sealing between blocks, O-ring sealing on sides |
| Support type | Leg support / Frame support |
| Surface treatment | Anti-rust paint on shell (for enclosed type) |
4.4 Electrical Parameters
Standard graphite condensers have no electrical requirements.
5. Core Component Selection
| Component | Common Brands | Features & Application |
|---|---|---|
| Graphite block | Quality domestic brands (e.g., Nantong Carbon) | Phenolic impregnation most common; Furan for higher temp and broader corrosion resistance; PTFE for strongest corrosion resistance |
| Sealing gasket | Quality domestic brands | PTFE gasket, corrosion resistant but requires proper clamping force |
| O-ring | Quality domestic brands | FKM / PTFE enveloped O-ring for side sealing |
| Shell (for enclosed type) | — | Carbon steel or stainless steel shell, selected by conditions |
| Liquid distributor (for falling film) | Quality domestic brands | Evenly distributes absorption liquid, ensures film formation |
| Gas-liquid separator (optional) | Quality domestic brands | Cyclone type or baffle type, separates non-condensable gas |
Customer brand preferences can be specified. For pre-owned equipment, availability depends on inventory.
6. Typical Application Fields
Chlor-alkali industry: HCl gas condensation, chlorine water cooling
Pesticide industry: HCl-containing exhaust gas condensation and absorption
Pharmaceutical industry: Corrosive solvent vapor condensation
Fine chemical: Mixed acid process condensation, organic acid vapor condensation
Metallurgical industry: Pickling process exhaust gas condensation
Environmental: Acid-containing exhaust gas condensation treatment
7. Design Standards & Certifications
| Standard | Description |
|---|---|
| HG/T 2370-2015 | Technical conditions for graphite chemical equipment (China) |
| HG/T 2059-2014 | Test methods for impermeable graphite equipment (China) |
| GB/T 150-2011 | Pressure vessels (applicable to shell portion) |
| ISO 9001:2015 | Quality management system |
| CE | Available upon request for international orders |
| EAC | Available upon request for Russia and Central Asia markets |
| GOST-R | Available upon request for Russian market |
8. Customizable Options
| Option | Details |
|---|---|
| Structural form | Round block / Rectangular block |
| Impregnation resin type | Phenolic / Furan / PTFE |
| Process function | Condensation only / Condensation + falling-film absorption / Condensation + gas-liquid separation |
| Hole diameter and count | Determined by process calculation |
| Pass count | Single-pass / Multi-pass |
| Shell material (enclosed type) | Carbon steel / Stainless steel / Lined |
| Liquid distributor | Tube type distributor / Overflow type distributor |
| Gas-liquid separator | Cyclone type / Baffle type |
| External insulation | Rock wool insulation + stainless steel or color steel cladding |
| Nozzle specifications | Matched to process piping |
9. Warranty Terms
| Equipment Status | Warranty Period | Warranty Scope |
|---|---|---|
| New equipment | 12 months | Graphite blocks, sealing gaskets, O-rings, shell (if any), inlet/outlet flanges |
| Refurbished equipment | 6 months | Graphite blocks, sealing gaskets, O-rings, shell (if any), inlet/outlet flanges |
| Pre-owned equipment (as-is supply) | 3 months | No additional damage to graphite blocks, main functional components |
Special note on graphite blocks: graphite is a brittle material. Damage caused during the warranty period by improper handling — bumps, mechanical impact or overpressure — is not covered. Gradual thinning of the graphite blocks through normal corrosive service is a natural phenomenon and likewise not covered by warranty.
Final warranty terms are subject to contract. All orders include installation guidance and remote commissioning support.
10. Packaging & Delivery
| Item | Packaging Method |
|---|---|
| Graphite blocks | Individual wooden box per block, inter-block cushioning protection, impact strictly prohibited |
| Shell (if any) | Shipped bare and secured with steel bands, with flange faces protected |
| Accessories/gaskets/O-rings | Wooden box or carton packaging |
| Liquid distributor/separator (if any) | Wooden box packaging |
Container capacity estimate (for reference only, subject to actual configuration):
Below 10m²: approximately 1-2 sets per 20'GP container
10～30m²: approximately 1-2 sets per 40'HQ container
Above 30m²: bulk vessel transport
Handling caution: graphite blocks are brittle. Throwing, rolling and impact during handling and loading are strictly prohibited. Use textile lifting slings; steel wire ropes must never be attached directly to the graphite blocks.
Installation service: on-site installation guidance is available. The blocks must be stacked one by one, with gaskets positioned, clamped evenly and a tightness test performed — we recommend carrying this out under technical supervision.
11. Information Required for Quotation
To obtain an accurate quotation, please provide the following information:
Name of condensation gas, composition, flow rate or condensation load
Condensation gas temperature and pressure (including non-condensable gas conditions)
Cooling medium type (cooling water/other) and inlet/outlet temperature
Required condensate outlet temperature
Whether falling-film absorption is required, with details of the absorption liquid
Whether gas-liquid separation is required
Required heat exchange area (if known) or process calculation data
Impregnation resin type preference
Structural form preference: Round block / Rectangular block
Whether a shell is required (enclosed/open type)
Whether external insulation is required
Equipment status preference: New / Refurbished / Pre-owned
Budget range and brand preference (if any)
Delivery terms: FOB/CIF/DDP
Destination port or delivery address (for freight calculation)