Liquid Desiccant Engineering Reference Guide

1 1 Reliable, high efficiency Desiccant dehumidification systems Liquid Desiccant Engineering Reference Guide 2 1 General Description ..2 Operating 3 Performance Estimating -- Sample Problem .. 4 Performance Curves .. 7 Engineering data Tables ..10 Equipment Drawings Small Packaged Unit .. 12 Conditioners ..14 Regenerators .. 22 Heat Exchanger Schematics ..25 Control and Piping Schematics .. 27 Installation Notes .. 29 Sample Specifications .. 32 Table of Contents 2 Kathabar Dehumidification Systems, Inc., the world leader in industrial humidity control, has manufactured dehumidification equipment for more than 75 years. The name "Kathabar," which is derived from Greek words meaning clean or pure air, describes what Kathabar equipment does best. The primary use of Kathabar is to provide precise and energy efficient air temperature and humidity control.

2 Kathabar maintains the process or space at the required condition regardless of weather or process variations. The "bacteria-free" benefit of Kathabar is an added feature to temperature and humidity control. Over the last 75 years, the design of K a t h a b a r e q u i p m e n t h a s b e e n continually evolving. Advances in heat and mass transfer technology and advances in construction materials have been incorporated. New product lines have been developed to serve the c h a n g i n g n e e d s o f i n d u s t r i a l , institutional, and commercial users as well as to reflect changes in the cost and availability of energy. Energy cost and availability issues have resulted in the development of the Twin-Cel air-to-air enthalpy recovery system. Today, KDS offers you the unbiased choice between Liquid and dry Desiccant systems to best meet your needs.

3 Kathabar Dehumidification Systems The latest product of this design evolution, the Kathapac FRP Series, is designed to provide additional values for all dehumidification applications. This completely corrosion-resistant line of dehumidification equipment utilizes an external heat exchanger with extremely efficient packing for greater longevity and performance than previous designs. Its values and benefits include the following: Simple, accurate control of performance Large airflow capacity Simple integration Low utility consumption Low maintenance cost Improved air quality Insensitivity to airborne contamination Long equipment and Desiccant life Kathapac FRP Series 3 Kathapac systems operate on the principle of chemical absorption of water vapor from air. The absorbent or Desiccant solution used, Kathene , is a water solution of lithium chloride salt. Kathene solution is non-toxic, will not vaporize, and is not degraded by common airborne contaminants.

4 The ability of Kathene to remove or add water vapor from the air is determined by the temperature and concentration of the solution. The concentration of Kathene can be adjusted so the conditioner delivers air at any desired relative humidity between about 18% and 90%. For a given Kathene concentration, lower solution temperatures enable the conditioner to deliver cooler, dryer air. The diagram above shows the basic elements of a Kathabar system. In operation, air to be conditioned is cooled and dehumidified by contacting Kathene in the conditioner. By continuously circulating the Desiccant through a heat exchanger, energy is extracted from the air and transferred to a coolant. The amount of heat extracted by the Kathabar dehumidifier is modulated by controlling coolant flow through the heat exchanger. Operating Principle FIGURE 1 Kathapac System Schematic 4 Sample Problem Design data Outside air requirements 1,000 SCFM Outside air summer design 95 F DB, 78 F WB Space maintained conditions 75 F, 30% 39 Gr/Lb Internal sensible load (including fan heat) 450,000 BTU/Hr Internal latent load 325,000 BTU/Hr Maximum diffusion temperature difference 20 F Available coolant 45 F chilled water Available heat source 200 F hot water A.

5 Determine conditioner leaving air temperature and airflow Leaving temperature = 75 F maintained - 20 F diffusion = 55 F Airflow = 450,000 BTU/Hr ISL = 20,833 SCFM 20 F diffusion x B. Select conditioner size from Engineering data Table, page 10 Unit size 2000 will accommodate 20,833 SCFM C. Determine maximum diffusion humidity difference Difference = 325,000 BTU/Hr ILL = Gr/Lb 20,833 SCFM x .68 D. Determine conditioner leaving air humidity Leaving air humidity = 39 Gr/Lb space maintained - Gr/Lb diffusion difference = Gr/Lb E. Check conditioner leaving air temperature and humidity to be sure that the desired performance falls within the conditioner performance envelope Desired performance is 55 F, Gr/Lb per Psychometric Chart, page 16, at a leaving air temperature of 55 F the conditioner can deliver air as dry as 11 Gr/Lb Therefore, conditioner can meet desired performance F. Determine air temperature and humidity entering conditioner 1,000 SCFM outside air @ 95 F DB, 78 F WB, 118 Gr/Lb 20,833 SCFM - 1,000 SCFM = 19,833 SCFM return air @ 75 F, 39 Gr/Lb Mix air temperature = 75 F + 1,000 SCFM (95 F - 75 F) = 76 F 20,833 SCFM Mix air humidity = 39 Gr/Lb + 1,000 SCFM (118 Gr/Lb - 39 Gr/Lb) = Gr/Lb 20,833 SCFM Therefore, air enters at 76 F, Gr/Lb Kathapac Performance Estimating 5 G.

6 Determine maximum coolant supply temperature that will achieve the desired conditioner performance Air enters conditioner at 76 F Gr/Lb Air leaves conditioner at 55 F, Gr/ Lb Air temperature depression = 76 F - 55 F = 21 F Air humidity depression = Gr/Lb - Gr/Lb = Gr/Lb See Air to Coolant Approach Curves (see Figures 3 and 4, page 7) With Kathapac FV, approach = F Maximum coolant supply temp. = 55 F - F = F With Kathapac FH, approach = F Maximum coolant supply temp. = 55 F - F = F Therefore, Kathapac FV Conditioner can provide desired performance with 45 F chilled water H. Determine the design moisture removal (MR) load on the conditioner Air humidity depression = Gr/Lb Airflow = 20,833 SCFM 20,833 SCFM x .643 x Gr/Lb = 358 Lbs/Hr (MR) 1,000 SCFM I. Determine regenerator capacity Lbs/Hr/Ft Air leaves conditioner @ 55 F, Gr/Lb (25% ) Kathapac Regenerator Capacity Curve (see Figure 6, page 8) Therefore, with 200 F hot water and 25% air, regenerator capacity = 40 Lbs/Hr/Ft J.

7 Calculate minimum regenerator face area required to handle design moisture removal load 358 Lbs/Hr - Ft min. face area 40 Lbs/Hr/Ft K. Select regenerator having sufficient face area using Kathapac Regenerator Engineering data Table, page 10 Per table, select a 10 FP Regenerator with 10 Ft face area L. Determine regenerator load using design moisture removal and face area of selected regenerator 358 Lbs/Hr = Lbs/Hr/Ft 10 Ft Face M. Determine regenerator heat requirements at design load, using Kathapac Regenerator Heat Requirements (see Figure 8, page 9) Regenerator load = Lbs/Hr/Ft Conditioner leaving humidity = 25% Conditioner leaving temperature = 55 F Therefore, 2,075 BTU/Lb x 358 Lbs/Hr MR = 743,000 BTU/Hr regenerator heat input 6 N. Determine conditioner cooling load at design conditions as follows: Calculate sensible cooling loads 20,833 SCFM x x (76 F - 55 F) = 472,500 BTU/Hr sensible load Calculate latent cooling load using design moisture removal and Kathapac Conditioner L Factor (see Figure 5, page 8) Regenerator load = Lbs/Hr/Ft Conditioner leaving humidity = 25% Conditioner leaving temperature = 55 F Therefore, L" Factor = 1,320 BTU/Lb 358 Lbs/Hr x 1,320 BTU/Lb = 472,600 BTU/Hr latent load Total cooling load = 472,500 BTU/Hr + 472,600 BTU/Hr = 945,100 BTU/Hr ( tons) FIGURE 2 System Flow Diagram 7 Kathapac Performance Curves FIGURE 3 Kathapac FV Air to Coolant Approach FIGURE 4 Kathapac FH Air to Coolant Approach 8 Kathapac Performance Curves FIGURE 5 Kathapac Conditioner L Factor FIGURE 6 Kathapac Regenerator Capacity 9 FIGURE 7 Pressure Drop through Kathapac Conditioners FIGURE 8 Kathapac Regenerator Heat Requirements 10 Engineering data NOTES 1.

8 Nominal horsepowers listed are for typical installations. Actual horsepowers may be higher or lower depending on performance requirements. 2. Normal operating weight should be used for sizing vibration isolators, if required. 3. Maximum operating weight should be used for structural calculations. 4. All weights are approximate. 5. All regenerators are furnished with FRP exhaust plenums. Kathapac Small Packaged Unit Conditioner and Regenerator Engineering data Unit Size Conditioner Regenerator Unit Weight, Lbs Airflow Air Face Sq. Ft. Nom. Pump HP Airflow Air Face Sq. Ft. Nom. Fan HP Avail. in. Nom. Pump HP Min. CFM Max. CFM Inlet SCFM Outlet ACFM Shipping Operating Normal Max. 240SP 400SP 600SP 1,500 2,500 3,750 3,000 5,000 7,500 6 10 15 2 630 950 1,480 830 1,260 2,000 1 3 2,400 3,300 4,400 3,300 4,400 5,800 4,400 5,900 8,000 Kathapac Small Packaged Units (SP Series) Conditioner Units Unit Size Airflow Air Face Sq.

9 Ft. Kathapac FV (Vertical) Kathapac FH (Horizontal) Min. CFM Max. CFM Nom. Pump HP Unit Weight, Lbs Nom. Pump HP Unit Weight, Lbs Shipping Operating Shipping Operating Normal Max. Normal Max. 240 400 600 1,500 2,500 3,750 3,000 5,000 7,500 6 10 15 2 2 3 1,300 1,600 3,100 1,950 2,200 4,300 2,600 3,000 4,300 - - - - - - - - - - - - 800 1200 1600 5,000 7,500 10,000 10,000 15,000 20,000 20 30 40 5 5 2,000 2,500 3,000 3,900 4,800 5,700 7,000 9,200 11,400 5 5 2,500 3,000 3,500 4,400 5,400 6,400 7,600 9,800 12,000 2000 2500 3000 4000 5000 6000 7000 12,000 15,000 18,000 24,000 30,000 36,000 42,000 24,000 30,000 36,000 48,000 60,000 72,000 84,000 48 60 72 96 120 144 168 10 10 15 15 20 20 25 4,800 5,600 6,400 7,900 9,400 10,800 12,400 8,500 10,500 12,000 15,000 18,000 21,000 24,000 13,000 15,500 18,000 22,500 27,500 32,500 37,000 10 10 15 15 20 20 5,600 6,600 7,600 9,400 11,500 13,100 15,000 10,000 11,700 13,700 17,200 19,800 23,300 27,300 14,000 16,500 19,500 24,500 29,000 34,000 40,000 Regenerator Units Unit Size Airflow Air Face Sq.

10 Ft. Nom. Fan HP Avail. in. Nom. Pump HP Unit Weight, Lbs Inlet SCFM Shipping Operating Outlet ACFM Normal Max. 3FP 6FP 475 950 1,900 630 1,200 2,500 3 6 3 2 650 900 1,200 800 1,100 1,650 1,100 1,600 2,300 10FP 15FP 20FP 30FP 40FP 3,160 4,700 6,300 9,500 12,600 4,200 6,300 8,400 12,600 16,800 10 15 20 30 40 5 10 15 20 2 2 2 2 2 5 5 10 15 2,100 2,700 3,400 4,600 5,800 3,300 4,000 4,800 6,400 8,500 5,000 6,200 8,000 11,000 14,500 11 Kathapac Regenerator Kathapac Small Packaged (SP) Unit 240 SP 6 FP Kathapac Equipment Pictures Kathapac Conditioners 3000 FV 4000 FH 12 NOTES 1. A CLEARANCE OF TWO FEET MINIMUM IS REQUIRED FOR MAINTENANCE ACCESS. 2. ALL PIPING, DUCTWORK, AND CONDUIT TO RUN CLEAR OF ALL ACCESS DOORS. Kathapac Small Packaged Unit UNIT SIZE COND. FAN HP NOMINAL FAN CFM AVAIL. @ 240SP 5 2,400 WC FIGURE 9 240 SP Kathapac Unit INLET PLENUM NOTES 1. DUCTW ORK ENTERING THE INLET PLENUMS MUST BE DESIGNED FOR A MAXIMUM VELOCITY OF 15 FT/MIN.