CASE STUDY PAPER INDUSTRY

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Justin Jordan
6 years ago
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1 CASE STUDY PAPER INDUSTRY Title of Measure ENERGY SAVING BY INSTALLATION OF AUTOMATIC PUMPING TRAP ACROSS DRUM DRYERS. Industry Sector Paper Client Details: One of the leading manufacturer in North-India. Year of Execution

New Application of UKL Automatic Pumping Trap (UAPT) in Paper Industry to Reduce In Specific Steam Consumption Typical application of steam in Paper Machine: Mostly the steam is used as indirect

2 New Application of UKL Automatic Pumping Trap (UAPT) in Paper Industry to Reduce In Specific Steam Consumption Typical application of steam in Paper Machine: Mostly the steam is used as indirect heating media in Paper industry. The moisture present in the paper is evaporated by using the convection and radiation heat received from the steam. Typical steam injection and condensate removal system may be represented as below: Moisture Evaporated from Paper Paper Steam Inlet Condensate Outlet Condensate Layer Syphon Cylinder Surface During study, it was observed that the condensate from drum dryers was being removed conventionally using steam traps. The machines were running at around 145 MPM for PM-1 & around 120 MPM for PM-2. The management is planning to increase the speed of the machines upto 300 MPM. The below figures describe the condition of steam condensate with respect to the varying machine speed. Fig. 1 Fig. 2 Fig. 3 Fig. 4

3 Fig. 1: Condensate accumulation in Dryer (very low speed) Fig. 2: Condensate slightly start moving at low speed (upto 100 MPM) Fig. 3: Condensate overflowing at medium speed (upto 250 MPM) Fig. 4: Formation of condensate ring (Rimming) at high speed M/C (>300 MPM) It was observed during the Plant study especially across PM-1 unit that the temperature of the drum was fluctuating considerably across few of the dryers, which may be due to the phenomenon of condensate overflowing and rimming. Advantages of installation of Automatic Pumping Trap (UAPT): In this system there is no need for steam traps. i.e. one can replace multiple steam trap modules (located in single section Pre Dryer, Post Dryer or MG) by a single UKL Automatic Pumping Trap. This system is highly suitable for all speed range of system including high-speed & high capacity machines. An UKL Automatic Pumping Trap ensures the effective condensate removal under normal circumstances as well as at low steam pressure instances which ultimately pushes out the condensate by applying motive steam. During normal circumstances, the UAPT works just like another trap and removes condensate. A rotary or stationary siphon is used to suck up the condensate along with the UAPT system. The steam consumption is very negligible (around 2 to 3 kg per ton of condensate removed from the cylinders) which makes this system highly lucrative over conventional steam trap based condensate removal system as well as the advanced condensate removal system like blow through or cascade system. The condensate collected from UAPT may be connected to the Flash vessel and condensate transfer pump which pumps the condensate back to boiler feed water tank. The plant already has the Flash vessel and Condensate pump in place. However, if the capacity of the same seems to be lesser, additional small system may be installed in parallel to the existing one in order to cater the surge load of the condensate. This system is much more efficient than the conventional methods like through traps and blow-through system.

4 Estimated Saving by installing UAPT: It is theoretically very difficult to quantify the savings that may be realized the system however, based on the UAPT performance for different heating applications has achieved around 10 to 30% reduction in specific steam consumption. However, based on the study conducted at one of the Paper Industries in Chandigarh, it has been observed that the specific steam consumption reduced from 2.4 to 1.9 kg/kg of product by installing single UAPT, in the Post Dryer section (Conventional 6 nos. of Ball Float Steam Traps replaced by single UAPT), thereby saving around 10 to 15% steam consumption as compared to the earlier one. The overall quantification of saving may be quantified as below: Avg. production of Paper (Single machine) : 65 TPD Avg. steam consumption across the Paper M/C : 143 TPD Hence existing avg. specific steam consumption : 2.2 kg/kg of Paper Estimated revised avg. specific steam consumption : 1.9 kg/kg Paper Hence, Estimated saving in steam consumption may be quantified as; = ( ) = 0.30 kg/kg of paper produced Thus, the estimated monetary saving that may be calculated; = 0.30 kg/kg x 65 Tons/day x 300 days/year = 5850 Tons per year Estimated saving in monetary terms may be quantified as; = 5850 Tons/year x Rs. 665/- per Ton = Rs lacs/year Considering system inefficiencies, to be on conservative side, we may consider estimated monetary benefit of only 60% of the above, which may be around Rs lacs p.a.

5 Estimated Bill of Quantity (BOQ) for the proposed system may be tabulated as below: Sr. Description Size (NB) Estimated Qty. (Nos.) 1 Piston Valves 2 Non Return Valves 3 UKL Automatic Pumping Trap (APT) 4 UKL Flash Vessel As per the steam & condensate lines & quantity of condensate 5 UKL Pressure Powered Pump Unit (UPPPU) The simple payback of the proposal may be around 6 to 7 months. Note: Cost of piping, fitting and labour charges not considered in the above proposal. Normally it is equivalent to the cost of accessories for similar projects. Still, the project has around 8 to 9 months payback, which is still highly feasible. Result : Hence, it is strongly recommended to install UKL Automatic Pumping Trap (UAPT) based condensate removal and recovery system instead of existing conventional steam traps. Central Sales Office: SC1, 5th Floor, Khadki, Pune-mumbai Highway, Pune , Ph

By: D K Singhal

Suggestive Improvements in Yankee Internal Design By: D K Singhal deveshksinghal@gmail.com Objective The objective of this presentation is to indicate the possibility of a modified design yankee tray for