CPAD & CPADM - Servivaneservivane.com.mx/wp-content/uploads/2013/06/CPAD-M_Product... · Overview ! Regeneration ! CPAD and CPADM Operation ! Cycle Knight and Dew Point Demand Controls

CPAD & CPADM Heatless Desiccant Dryers

5 – 3100 cfm

High Performance Products. Designed for you !

Overview

�  Regeneration

�  CPAD and CPADM Operation

�  Cycle Knight and Dew Point Demand Controls

�  Design Criteria

�  Competitive Analysis

�  Competitive Review

�  Appendix- Component Information

Quality Dryers to Meet Customers’ Needs

•  Field proven design •  Non-proprietary components •  Quality control throughout production •  Every unit receives a functional test

Water Removal from Compressed Air Systems

For a 25 hp compressor, almost 1 gallon per day of condensate still passes downstream

•  Prevent Freeze-Up in Sub-Zero Ambient Conditions –  Temp of the outlet air is a few degrees higher than inlet –  Dewpoint at -40°F ensures no condensation

•  Process Industries/Control Air •  Paint Shops •  Tool Life •  Quality Control

Why Dry Compressed Air to -40°F?

Heatless Air Dryers - 14% Purge �  CPAD Series - Heatless

�  CPADM - Mini Series Heatless Air Dryers

Externally Heated Air Dryers - 7 % Purge Blower Purge Air Dryers - 0% Purge Except for Cooling Cycle - 1.45% Heat of Compression Air Dryers - 0% to 1.45% (only for centrifugal)

Four Types of Regenerative Dryers

WET AIR

DRY AIR

Vapor Pressure Adsorption: Adsorption takes place due to differing vapor pressures; the high vapor pressure of saturated compressed air at 100 PSIG compared to the low vapor pressure of dry desiccant resulting in molecular attraction. Vapor Pressure: As liquids physically change into a gas (vapor), their molecules travel with greater velocity to break off and form vapor. These molecules create a “vapor pressure,” the temperature corresponding to any given vapor pressure is the boiling point of the liquid and also the dew point of the vapor.

DRY AIR

WET AIR

Heatless regeneration takes place due to differing vapor pressures. The low vapor pressure of dry compressed air at 0 PSIG compared to the higher vapor pressure of moisture on the desiccant. Heat of Adsorption is retained in the bed to assist in desiccant regeneration.

Regeneration

Adsorption with Respect to Flow

• Vessel velocity less than 55 ft./min.– Ensures air stays in contact with desiccant– Prevents desiccant carry-over downstream

• Contact time: 5 seconds (minimum)– Accounts for fluctuations in system pressure– Accounts for fluctuations in compressor operation (start/stop)

• Low pressure drop: 3 psid or less– Reduces compressed air consumption– Reduces energy costs– Reduces over-sizing equipment– Reduces maintenance costs

Adsorption Enhancement Active Bed Support

Minimum Inlet Temp: 70°F Maximum Inlet Temp: 120°F Air Inlet Pressure: 100 psig

100% Saturated Vapor

Operating Conditions:

Standard Specification

NEMA Cycle:

�  -40°F Version is 10 min

�  -100°F Version is 5 min (optional)

Purge Flow: 14%

Power: 115V, 1~, 60 Hz

3 psi or less drop at rated flow

Min 5 sec desiccant contact

Best Practice Installation

1. 2. 3. 4.

1. CP Rotary screw air compressor with built-in aftercooler 1a. Optional centrifugal moisture separator between compressor and filter

2. CPFS, fine coalescing filter: 0.1 Micron, .008 ppm carryover

3. CPAD or CPADM heatless regen dryer

4. CPFD, particulate dust filter: 1 Micron

Receiver

Tank 1a.

CPAD/M Flow

INC.

PH/EH-SERIES PROCESS &INSTRUMENT DRAWING

INC.INC.

PH/EH-SERIES PROCESS &INSTRUMENT DRAWINGPH/EH-SERIES PROCESS &INSTRUMENT DRAWING

CPAD/M Series

Cycle Knight Controller

LED Display includes: Left Tower Drying

Right Tower Drying Left Tower Regeneration

Right Tower Regeneration Demand Cycle LED Sequence indicators 5min/10min select switch available ON/OFF push button Dryer start from zero after shutdown or power failure.

LED indication of alarms Dry contacts for alarm outputs

- High Humidity - Failure to Shift

Alarm reset button

Cycle Knight with Dew Point Demand

Dew Point Demand (DPD)

Measurement Range: +68°F to -148°F Accuracy: ± 3.6°F (2°C) Relay output 3A @ 240 VAC Quantity of 2 with 4-20 mA output for remote annunciation

Monitors dew point at the outlet until it is above -40ºF. At better than -40ºF dew point, the dryer does not purge but continues to cycle and dry air.


Digital dew point display Adjustable dew point settings Added Protection

–  High humidity alarm –  Failure to shift alarm


Extend the drying cycle without purging Reduces purge loss

–  Reduces compressed air consumption –  Saves energy

Reduces tower cycling –  Extends valve life –  Saves maintenance time

The option that pays for itself

Design Criteria Vessel Velocity & Contact Time

Air speed is very important in dryer design. If the speed it too high several problems will occur:

§  The desiccant will lift and then drop against the strainers, which will damages the desiccant and possibly the strainer too.

§  The beads will hit against each other causing “dusting”. This will lead to reduced PDP performance and lifetime of the desiccant, as well as very short dust filter lifetime

§  Hollow channels will be formed meaning that air can escape through the tower without proper contact with the desiccant, leading to poor PDP.

§  There will not be enough “contact time” between the air and the desiccant to allow the water vapour to transfer from one to the other.

Air speeds are reduced by having vessels with a large diameter and contact time is increased by having tall towers full of desiccant.

Designing vessels which are thin also has some “advantages”

§  The smaller the diameter of the vessel, the cheaper the vessels become

§  All of the “bad” effects remain hidden until some weeks/months after the dryer has been started

§  Low contact time can be “fixed” by having very tall vessels, but that increases pressure drop.

Watch out for tall vessels with a narrow diameter…..

Vessel Velocity & Contact Time – Something To Think About

Design Criteria

Purge Flow

The purge flow required (as a % of inlet capacity) depends on two main parameters:

§  The pressure of the incoming air

§  The nominal temperature of the incoming air

The minimum required purge air is based directly on these two criteria

Design Criteria

Inefficiencies a = free water b = heat losses c = temperature differences d = purge flow pressure > atmospheric P e = RH purge air < 100 % f = efficiency desiccant < 100 %

a

b c

d

e

f

Design Criteria

§  Inefficiencies are caused by flow restrictions, pressure drops, heat loss, short contact times, all of which are caused by smaller cheaper components

§  The inefficiencies are going to be bigger for machines with a higher pressure drop and machines which purge in the same direction as the regular flow.

§  Many companies quote regeneration but “forget” about the re-pressurization

Purge Flow – Something To Think About

Design Criteria

Inefficiency accounts for more than 12.5% usage

The amount of desiccant in the bed determines the PDP performance :

§  There is a fixed relationship between the water saturation level of desiccant and the PDP it will provide

§  More desiccant added to a dryer, the lower the water saturation and the better the PDP

§  Over a long period of time desiccant deteriorates, adding extra desiccant can counteract this ageing process. The cheaper desiccant the faster the desiccant deteriorates

The two most important parameters are the weight of desiccant in the bed and the grade of that desiccant. Lower grades of desiccant require changing more often.

Desiccant Performance & Quantity

Design Criteria

§  Desiccant is expensive - overfilling is not a cheap benefit

§  Extra desiccant requires extra room in the vessel – making them more expensive

Desiccant Performance & Quantity – Something To Think About

Design Criteria

Without significant overfilling, what happens to the PDP after 3 years?

Brochure Highlights

Competition Summary – Hankison HHS, HHL & HHE

§  Start by building a good impression

§  Technical knowledgeable

§  Lots of “important” numbers

§  Safe and experienced

§  Units good for a range of PDP’s

§  “No job is too small”

§  Give impression that they’ve thought of everything.

§  A very poor valve has become a selling feature

§  This valve used up to 4000 scfm model!!

Competition Summary – Hankison HHS, HHL & HHE Brochure Highlights

§  Each version is explained commercially

§  Technical details come second

§  Clear cut benefits are defined

§  Examples of potential energy savings given in the brochure

§  Apparently the control system is very comprehensive and provides a lot of customer benefit.


§  18 models in the range

§  Biggest unit has a capacity of 5400 cfm

§  No correction factors for temperature

§  Purge loss is quoted at 13.7%


§  HHE = Totally basic version – simple timer card only

§  HHL = version with variable timer control basic control

§  HHS = version with “Energy Efficient SensaTherm” control

§  SensaSorb desiccant used, which is actually activated alumina

§  Filtration not included as standard

§  Regular voltages, pressure and approvals accommodated

Product Overview & Basic Details


§  Towers are tall and thin – beware high speeds and short contact time

§  Brochure states slow speeds and long contact time. Based on actual measurements, their speed is 59.6 ft/min, ours is 47.8 ft/min. Their contact time is 6.0s ours is 7.22s.

§  Customer has to pipe to the top and bottom of the unit

§  Quoted pressure drop of 4.9 psi which indicates restrictive piping/valves – which is also bad for regeneration efficiency

§  P & ID shows lots of piping, valves and elbows – high pressure drop

§  No desiccant quantities given. Brochure states 30% overfill, but 30% of what?

§  Quote 15.5% average purge (13.7% for the regen), which is more or less impossible, particularly when you consider the pressure drop.

Vessels, Piping, Desiccant & Purge


§  Either shuttle valves or 2x small butterfly valves are installed which only have a partial opening, causing pressure drop.

§  The same type of valves are used to control the blow off, thereby restricting regenerating air and causing inefficiencies

§  The shuttle valves are totally aluminum, so there is a good chance of the threads being destroyed by dissimilar metals, causing leaks and possible breaks.

§  Only the HHS 4100 and above use butterfly valves check valves, the smaller machines use potentially unreliable but cheaper shuttle valves, which are prone to “hanging”.

§  None of the valves are stainless steel and none of them have Teflon seats

Valves and Components


§  Only one safety valve on the whole dryer, not one per tower (very unsafe)

§  To service the shuttle valve, four flanges plus the couplings will have to be dismantled – very expensive for maintenance

Competition Summary – Hankison HHS, HHL & HHE Valves and Components

§  An extra set of silencers are provided with the unit – probably because they can’t afford any back pressure, otherwise the shuttles will hang-up.

§  The silencers do not have integrated safety valves, so if they do get blocked the dryer will stop working

§  Silencers of this size are going to be expensive to replace and will be prone to freezing if put outside

Competition Summary – Hankison HHS, HHL & HHE Valves and Components

Sensors and Instruments


§  No electronic pressure sensors, only gauges – a severe limitation:

§  Control panel cannot determine if the inlet pressure is too low.

§  Control panel cannot determine if the regeneration air has the correct pressure

§  Moisture indicators fitted, which only turn to a different colour once it’s too late and the dryer has already failed – and even then you have to be in fron of the machine

§  Temperature sensors are fitted on the HHS version in the desiccant bed, but not on the inlet pipe. Therefore a warning is not possible if the inlet temperature is too high

§  No PDP sensor, therefore no way to accurately determine or provide the PDP on screen.

§  Fail to shift alarm is standard – probably because it happens a lot J

The only measured parameter entering the control system is the desiccant bed temperature, and only on the HHS version.

The control system, and therefore the user, is running blind.

The remote alarm is wet air in the system!!

Sensors and Instruments


§  Attractive display, which as standard offers the customer the possibility to change the timer cycle.

§  4 fixed cycles for different PDP’s

§  1 of the cycles will destroy the desiccant in the long term

§  No temperature, pressure or PDP sensors fitted

§  LED’s provide information about assumed dryer status, including service warnings, which cannot be confirmed as there are no sensors.

§  Alarm for valve actuation failure, no other alarms possible

§  No alarm for high PDP, as it’s not measured

§  No compressor load/unload synchronisation function

HHL Controller – Purge Economizer


§  Attractive display, which as standard offers the customer the possibility to switch the timer cycle between 4 fixed routines for different PDP’s

§  Temperature sensors fitted in the desiccant bed enable the controller to estimate bed saturation, and switch towers accordingly. This system is very approximate and provides only small savings

§  LED’s provide information about assumed dryer status which cannot be confirmed as there are only temperature sensors

§  Alarm for valve actuation failure, drain failure, and high pressure drop across the filters, but nothing else.

§  No alarm for high PDP, as it’s not measured

§  No compressor load/unload synchronisation function

§  Small text display for service reminders

HHS Controller – SensaTherm


§  High pressure drop, 5 psi – indicating much larger restrictions through the valves, piping and vessels compared to the CPAD range, which is 3 psi. Difference represents 1% compressor power.

§  Quote a low purge flow, but this is most unlikely, either the PDP is not reached (who knows, there’s no measurement) or the real losses are much higher. The valves are very restrictive, so the purge inefficiencies will be greater than those for the CPAD.

§  HHL version – low energy savings, especially as there is no compressor sync contact.

§  HHS SensaTherm, very approximate energy saving with no sensors providing reliable data for the controller

Energy Savings


§  Thin vessels mean fast air speed which means short desiccant lifetime.

§  Valves and other key components have been selected to keep costs down, with the consequence of flow restrictions, average materials and high pressure drops.

§  Control systems provides what looks like great data, but it’s all based on assumptions as there’s no measured inputs. Energy saving device rather approximate. No PDP measurement and no readout.

§  High pressure drops, very limited control system and questionable energy savings limit the appeal of this dryer range.

Summary


Competitive Review – Airtek Heatless 1000 scfm

§  Literature has no temperature correction factors

§  150 scfm purge vs. CPAD 140 scfm

§  CPAD has 725 lbs/tower vs. 600 lbs/tower of desiccant

§  Towers narrower, less desiccant, cheaper to produce

§  5 psi pressure drop – not good (CP = 3 psid)

§  “Pressure swing absorption”

§  Cheap non-lube switching valve

§  Horrible master control

§  Ugly diagonal pole

§  Unload cycle lock option

§  Less expensive compared to CP

Competitive Review – Great Lakes

§  20-25% less desiccant compared to CP

§  Smaller towers in height and width than CP

§  Same diaphragm valves that CP has on the EH dryers

§  Claims average 5-7 years valve life before seal kit needs to be replaced – Not true; we use same valves

§  NEMA-12 standard vs. CP NEMA-4

§  Warranty problems can only be claimed on initial purchase, from original customer

§  Warranty states 2 years in brochure; only 1 year parts and labor in warranty statement

§  Pressure drop not listed

§  Offers humidity probe as well as dew point probe

Competitive Review – Donaldson 500 scfm

§  Have angle piston valves up to 600 scfm

§  Requires desiccant to be changed every 3 years

§  Couldn’t find dimensions or weight of dryers

§  No pressure drop listed

§  They warn about “desiccant powdering downstream”

§  Clean and lube valves as needed, no specific time frame

§  $1180 adder for Failure to Shift Alarm – expensive

§  Inlet temp over 100°F – suggests MS desiccant adder

§  Adder for -100 PDP and separate adder for MS desiccant

§  10 year warranty on valves

§  Size and weight is lighter than CP

§  Hardly any technical information

Competitive Review – Zeks Eclipse

§  90-8000 scfm

§  Selector switch for 39°F dewpoint – can you say “self-destruct”

§  Between -80°F to -100°F, decreases 20% air flow capacity

§  Up to 15% purge

§  No pressure drop listed

§  No lbs/tower of desiccant listed

§  No temp/pressure de-rating information

§  Rebuild valves every 2 years

Competitive Review – Zeks Hydronix §  Models are very similar

§  CP standard vs. Zeks options

§  Gauges

§  Relief valves

§  NEMA 4 cubicle

§  Air Miser system vs. air demand with CP

§  Filter packages ship separately

§  CP dryers weigh more – presumed to have more desiccant

§  Use diaphragm angle valves

§  Restricted air flow

§  Very comparable to the CPADM

§  No warranty information

We Have A Very Strong Product

We Offer Great Value Over The Lifetime Of The Machine

The Customer Can Only Evaluate This Value If We Talk About It

To Summarize ……

High Performance Products. Designed for You!

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Appendix Component Information

The Valves

• CPADM uses solenoid valves• CPAD to 1.5” uses ball valves

• CAPD 2” and greater uses butterfly valves

Ball Valves

Used on CAPD up to 1.5” diameter

Butterfly Valves

Butterfly Valves

Used on CAPD with 2” diameter or greater

Check Valves

Used from ½” to 2” connections

Check Valves

Used for >2” connections

Low pressure drop saves compressed air, electrical cost,

over-sizing equipment and maintenance costs

Activated Alumina Desiccant



Dew Point Curves

60.

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Date High Performance Products. Designed for you !

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CPAD & CPADM - Servivaneservivane.com.mx/wp-content/uploads/2013/06/CPAD-M_Product... · Overview ! Regeneration ! CPAD and CPADM Operation ! Cycle Knight and Dew Point Demand Controls