Claw Type Dry vacuum pump v/s Coated Horizontal Dry screw vacuum pump
Introduction
The Dry Vacuum Pumps are gaining prominence in the Process Industries owing to the high quality of Vacuum, lower maintenance and Clean Process with a minimal environmental footprint. Since they are engineered to handle a robust environment, they have been proven as a trustworthy and optimum solution for the pharmaceutical industries and those dealing with chemical processing.
Let us understand what a Dry vacuum pump is, and why is it preferred?
As the name suggests, dry vacuum pumps do not require any fluid to create a vacuum, and hence the chances of product contamination are zero. The pumps have an integral cooling jacket to offset the heat generated during the pumping process.
The dry vacuum pumps are mainly categorized as under:
1. Screw vacuum pump
2. Claw vacuum pump
Let us understand each one in brief.
1. Screw vacuum pump
It is a kind of suction and exhaust instrument that uses a pair of screws to make a high-speed reverse rotation in the pump housing. In this, two screw rotors rotate in opposite directions in the pump shell with high speed to draw in vapours and then are discharged out. The screw vacuum pump is an advanced and improved design of a vacuum pump that results in lower electric energy consumption and maintenance-free advantages.
2. Claw vacuum pump
In this type of pump, multi-stage rotors are used wherein each stage comprises two rotors. The two rotors rotate in opposite directions to create compression and expansion. In this pump, two compression cycles are completed through a full rotation of claws. As they rotate, the claws take in Vapour through the inlet, and the pump compresses the vapour.
What is a coated dry vacuum pump?
To protect the base metal against the chemical attack, a coating is provided to the vacuum pumps. It is a chemically inert layer, made up of polymer applied for protection on metallic surfaces. The main drawback of coating is that it cannot protect against abrasion.
We are giving a detailed comparison of our four-stage Vertical uncoated Dry vacuum pump against the Screw coated Dry vacuum pump.
COMPARISON OF OUR DRY VACUUM PUMP WITH OTHER COATED DRY VACUUM PUMP
|
Sr No |
Selection Parameter |
Vertical Uncoated Dry Claw type Vacuum Pump |
Horizontal Coated Dry Screw Type Vacuum Pump |
|
|
|
Origin |
India (100% Made in India) |
Korea/Germany/China/Japan |
|
|
Application point of view |
||||
|
1 |
Suitability for Low boiling solvent |
Yes |
Yes |
|
|
2 |
High Boling solvents like Toluene/ Xylene
|
Yes |
No Condensation take place in pump causing damage to coating |
Coated pump suitable up to 80 Deg C & hence not suitable |
|
3 |
Permissible Temp |
120 Deg C |
80 Deg C |
|
|
4 |
High compression ratio |
Yes. Pump alone work for 1 torr distillation. |
No. High compression ratio increase temp in pump beyond 80 Deg C. Reducing life of coating |
|
|
5 |
Higher Gas inlet temp |
Yes .Allowed 55 Deg C As pump suitable for 120 Deg C working temp. |
NO. At higher gas temp, coating will be damaged & screws will be seized |
|
|
6 |
Can Handle condensate? |
Yes. 60 LPH handling capacity. The Vertical design enables the condensate to drain out |
No Only 10 LPH Handling capacity. Due to a Horizontal design, the condensate remains inside. Damage to coating, bearings & mechanical seal |
|
|
7 |
Can handle Particulate in case of sublimation |
Yes. The Particulate can easily drain out. Uncoated & hence no damage & No costly maintenance |
No. The Coatings on the Screw might face erosion. Coating life will be shortened. |
|
|
8 |
Can handle carbon particles in case of gas cracking at High temp? |
Yes. Not affecting pump performance |
No. The PEEK/PFA/Ni+ PFA/Ni + PEEK Coating will be damaged resulting in long drawn and expensive maintenance of the Screws and the Coatings |
|
|
9 |
Can handle corrosive gases, acidic vapour? |
Yes. Our pumps are working for Thionyl Chloride and other Acidic Vapours |
Yes so long coating is intact. Once coating damaged/eroded, the corrosion will be faster. |
|
|
Pump performance |
||||
|
11 |
FAD Capacity@2900 RPM |
300 M3/HR |
250-267 M3/HR |
|
|
12 |
Ultimate vacuum |
0.06 Torr |
0.5 to 1 torr |
|
|
13 |
Capacity @ 10 torr |
300 m3/hr |
250-267 m3/hr |
|
|
14 |
Capacity @ 1 Torr |
300 m3/hr |
240 m3/hr |
|
|
15 |
Capacity @0.1 torr |
100 m3/hr |
Zero |
|
|
16 |
Permissible discharge pressure |
1300 mbar |
1013 mbar |
|
|
17 |
Can we install a scrubber in discharge ? |
Yes |
No |
|
|
18 |
Will increase in back pressure create problem in pump performance? |
No |
Yes. Motor may trip & condensation take place |
|
|
19 |
Connected Load? |
15 HP |
10 HP |
|
|
20 |
Absorbed power @ 10 torr? |
12 Amps |
12 Amps |
|
|
21 |
Motor Tripping |
Never |
Some times when condensation take place in pump or particulates are trapped between two screws. |
|
|
From Maintenance point of View |
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|
22 |
Need to replace motor |
No |
Yes |
|
|
23 |
Do we need to send pump outside of the Plant for maintenance & Coating? |
No |
` |
|
|
24 |
Opening of bearing & Assembly |
Easy |
Easy |
|
|
25 |
Dismantling of Pump? |
Easy at site |
Send to work shop. Takes long time |
|
|
26 |
Assembly of pump |
Easy at site with filler gauge |
Not easy. Takes long time. If clearance are not maintained blank off vacuum cannot be achieved. |
|
|
27 |
One year non interrupted services |
Yes. We have many installations running for more than 1 year without service break down. |
No. Coating & Mechanical seal may fail any time at the cost of Production losses & Expensive maintenance cost |
|
|
28 |
Maintenance cost |
Negligible. Cost for consumable like grease &oil. No other maintenance cost |
Very high coupled with long production losses. |
|
|
29 |
In case of Pump Jamming/Seizure? |
Pump will be free after pouring diesel or suitable solvent. Will take 2-3 hours. No damage to pump internals in absence of coating |
If coating damage than recoating will cost close to INR 4.0 Lac & pump will be out of service for Two months. Recoating may not reliable |
|
|
30 |
Oil bath / Grease chamber sealed by? |
By Lip Seal which is Economical & reliable takes very less time Fitment 1 hours Cost of lip seal not more than 10K |
By Mechanical seal. Expensive time consuming & skilled person required. Repair time 2 days. Cost of Mechanical seal INR 50K - 1.0 Lac |
|
|
31 |
Cost of consumables Like oil, grease , bearings? |
Economical since indigenous parts. Readily available in market |
Imported grease & Oil. Not easily available in market |
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32 |
Can dry vacuum pump work in Multiple applications? |
Yes |
No. Suitable for low boilers like Methanol, Acetone, Ethyl acetate. But not suitable for Toluene/Xylene & other high boilers |
|
|
33 |
Solid Foundation |
Not Required |
Required |
|
|
34 |
Foot Print |
1200 X 1100 MM |
2000 X 500 MM |
|
|
35 |
Vibration |
Normal. No solid foundation needed. |
Solid foundation needed to protect mechanical seal & proper height needed to install post condenser & receiver for solvent recovery & to reduce back pressure. |
|
Coated Horizontal Dry Screw Vacuum Pumps are not suitable for following Solvents
|
Solvent |
Boiling Point (°C) |
Solvent |
Boiling Point (°C) |
Solvent |
Boiling Point (°C) |
|
Acetic Acid |
118.0 |
Benzene |
80.1 |
tert-Butanol |
82.5 |
|
Acetic Acid Anhydride |
139.0 |
Iso-Butanol |
107.7 |
Chlorobenzene |
131.7 |
|
Acetonitrile |
81.6 |
n-Butanol |
117.7 |
Cyclohexane |
80.7 |
|
Dimethyl Acetamide |
166.1 |
Ethylene Dichloride |
83.5 |
Hydrochloric Acid |
84.8 |
|
Dimethyl Formamide |
153.0 |
Ethylene Glycol |
197.5 |
Iso-Propanol |
82.3 |
|
Dimethyl Sulfoxide |
189.0 |
Heptane |
98.4 |
n- Propanol |
97.2 |
|
Pyridine |
115.3 |
Xylene |
140 |
Toluene |
110.6 |
Today our dry vacuum pump is a preferred choice in the chemical & Pharmaceutical segment.
Zero maintenance & less repair cost, and less downtime, are significant factors for our pumps' success.
Conclusion
The Vertical Claw type dry vacuum pumps offer a hygienic and fluid free vacuum solution for the pharmaceutical and chemical industries. They are best in handling the fluids, causing corrosiveness. The design of a dry vacuum pump offers a low operation and maintenance cost with no major impact on the environment.
About HIS Pumps & Systems Private Limited
HIS Pumps and Systems is a Solution Provider for Claw Type Dry Vacuum Technology to the Process Industries. With over 120+ Installations and with a combined experience of more than 25 Years, we have a proven track record of providing Premium, Proven and Reliable Vacuum Solutions to Pharmaceutical, Chemical, Agro Chemical and Fertilizer Industries.
