10 Considerations for Optimum Use of Vacuum Technology

Vac­u­um tech­nol­o­gy plays a huge role in the pack­ag­ing of food­stuffs and oth­er prod­ucts. Vac­u­um is need­ed for every­thing from vac­u­um pack­ag­ing to tubu­lar bag, blis­ter, and ther­mo­formed pack­ag­ing. With­out vac­u­um, it would also be impos­si­ble to han­dle and trans­port car­tons or auto­mate pal­letiz­ing and order pick­ing sys­tems. Var­i­ous fill­ing machines also use vac­u­um to feed in the prod­uct or han­dle pack­ag­ing (pick & place).

In con­trast to com­pressed air tech­nol­o­gy, many users find vac­u­um tech­nol­o­gy quite tricky to under­stand. This is why vac­u­um pumps are often used incor­rect­ly or their out­put is unnec­es­sar­i­ly exces­sive. This results in unsat­is­fac­to­ry results, dis­rup­tion-prone process­es or exces­sive ener­gy or oper­at­ing costs. The 10 con­sid­er­a­tions below have been put togeth­er to help you use vac­u­um tech­nol­o­gy as effec­tive­ly and effi­cient­ly as pos­si­ble so that you can opti­mize process­es and cut oper­at­ing costs.

1. Understanding the physics of vacuum

The main pur­pose of vac­u­um pumps and vac­u­um sys­tems is to suck air out of a closed sys­tem in order to gen­er­ate vac­u­um. This means they gen­er­ate a lev­el of pres­sure that is low­er than the atmos­pher­ic or ambi­ent pressure.

In pack­ag­ing tech­nol­o­gy, you can use vac­u­um to suc­tion, evac­u­ate, shape, press, hold, move, fill, and trans­port. The lev­el of vac­u­um used depends on the appli­ca­tion, but always ranges from between 1 and 900 mil­libars [mbar] (absolute). Assum­ing atmos­pher­ic pres­sure (air pres­sure) of 1,000 mbar, this vac­u­um lev­el would be between 10 and 99.9 per­cent (fig. 1).

In addi­tion to the vac­u­um lev­el achieved by a vac­u­um pump (known as the ulti­mate pres­sure), a vac­u­um pump’s pump­ing speed is anoth­er key vari­able. The pump­ing speed indi­cates how much air a vac­u­um pump is able to extract with­in a cer­tain peri­od of time. Pump­ing speed is nor­mal­ly spec­i­fied in cubic meters per hour [m3/h]. Both tech­ni­cal para­me­ters are relat­ed to one anoth­er. This rela­tion­ship is depict­ed in the so-called pump­ing speed curve (fig. 2).

2. Choosing the ideal vacuum generator

There is an array of dif­fer­ent types of vac­u­um tech­nol­o­gy. The fol­low­ing mechan­i­cal vac­u­um pumps or blow­ers are main­ly used in the field of pack­ag­ing tech­nol­o­gy (fig. 3):

1. Dry-run­ning rotary vane vac­u­um pumps
Dry-run­ning rotary vane vac­u­um pumps are ide­al for a vari­ety of pack­ag­ing process­es. These pumps are able to reach a max­i­mum vac­u­um lev­el of 100 mbar. How­ev­er, the pump­ing speed should not exceed 40 m³/h as the vanes in larg­er vac­u­um pumps of this type wear more and thus result in exces­sive increas­es in main­te­nance effort and the relat­ed costs.

2. Oil-lubri­cat­ed rotary vane vac­u­um pumps
Oil-lubri­cat­ed rotary vane vac­u­um pumps achieve a vac­u­um lev­el of 0.1 mbar. They are the stan­dard in vac­u­um pack­ag­ing but may also be used in many oth­er appli­ca­tions through­out indus­try. Rotary vane vac­u­um pumps are able to cov­er pump­ing speeds from 3 to 1,600 m³/h. The oper­at­ing flu­id oil is trans­port­ed in an inter­nal circuit.

3. Dry claw vac­u­um pumps
Dry claw vac­u­um pumps do not require any oper­at­ing flu­ids in the com­pres­sion cham­ber. They have a con­tact-free oper­at­ing prin­ci­ple and are there­fore near­ly main­te­nance-free. They achieve ulti­mate pres­sures of up to 40 mbar and can be reg­u­lat­ed from 20 to 80 Hertz rota­tion­al speed, which makes them suit­able for process­es in which chang­ing out­put require­ments should be met on a demand-dri­ven basis. Com­mon pump­ing speeds are between 40 and 1,000 m³/h.

4. Dry screw vac­u­um pumps
Dry screw vac­u­um pumps also do not require oper­at­ing flu­ids to com­press the extract­ed air. They achieve a vac­u­um lev­el of 0.1 mbar and below. Since most appli­ca­tions oper­ate at much high­er pres­sures, screw vac­u­um pumps are gen­er­al­ly only used in larg­er vac­u­um pack­ag­ing machines as an alter­na­tive to a rotary vane vac­u­um pump with an addi­tion­al vac­u­um booster.

5. Side chan­nel blowers
One of the dis­tin­guish­ing fea­tures of side chan­nel blow­ers is their high pump­ing speed. Because they only achieve low dif­fer­en­tial pres­sures, they are only able to achieve a max­i­mum vac­u­um lev­el of 500 mbar. They are there­fore ide­al­ly suit­ed to appli­ca­tions that require a high pump­ing speed in com­bi­na­tion with a low vac­u­um lev­el. While side chan­nel blow­ers are main­te­nance-free, they are less ener­gy-effi­cient if they are used close to their per­for­mance limits.

3. Dimensioning the vacuum supply

It is impor­tant for users to exact­ly under­stand their par­tic­u­lar process and to know which vac­u­um lev­el and pump­ing speed are required for it. Uncer­tain­ty often leads to choos­ing a vac­u­um pump with exces­sive dimen­sions, result­ing in unnec­es­sary ener­gy and oper­at­ing costs. In sce­nar­ios with chang­ing process para­me­ters, we rec­om­mend vac­u­um pumps that can be con­trolled on a demand-dri­ven basis and that either con­stant­ly main­tain the required vac­u­um lev­el or guar­an­tee a con­sis­tent pump­ing speed. We always rec­om­mend con­sult­ing a vac­u­um spe­cial­ist. Busch Vac­u­um Solu­tions offers spe­cial vac­u­um audits, which exam­ine cur­rent process­es and high­light poten­tial areas of improvement.

4. Choosing between a central or local vacuum supply

The deci­sion between a cen­tral vac­u­um sup­ply for an entire plant or mul­ti­ple vac­u­um con­sumers, and a decen­tral­ized vac­u­um sup­ply where each indi­vid­ual machine has its own vac­u­um pump, can have a deci­sive impact on your pro­cure­ment and oper­at­ing costs. It is there­fore impor­tant to care­ful­ly weigh your options. Indi­vid­ual vac­u­um pumps that are installed inside a machine or in close prox­im­i­ty to it are cheap­er than a cen­tral vac­u­um sup­ply, not least because you no longer have to cov­er the costs for procur­ing and installing a pipeline sys­tem. How­ev­er, it is impor­tant to remem­ber that a cen­tral vac­u­um sup­ply uses far few­er vac­u­um pumps than a decen­tral­ized solu­tion. Oper­at­ing costs are reduced because your main­te­nance and ener­gy costs are low­er. What is more, a cen­tral vac­u­um sup­ply can be set up out­side of pack­ag­ing or pro­duc­tion areas. This means that no noise or heat builds up at your work sta­tions. A cen­tral vac­u­um sup­ply with a con­trol unit also makes it eas­i­er to meet out­put require­ments on a demand-dri­ven basis and can be oper­at­ed over a broad­er out­put spec­trum. You should also con­sult a vac­u­um expert when decid­ing for or against a cen­tral vac­u­um sup­ply. Busch Vac­u­um Solu­tions has many decades of expe­ri­ence in design­ing and build­ing cen­tral vac­u­um sys­tems and is able to offer its cus­tomers tai­lor-made solutions.

5. Increasing efficiency with vacuum vessels or buffers

Vac­u­um ves­sels on indi­vid­ual vac­u­um pumps and even on larg­er vac­u­um sup­ply sys­tems can save huge amounts of ener­gy. They can be installed between the vac­u­um pump or vac­u­um sys­tem and the con­sumers. Using a sim­ple con­trol mech­a­nism, the vac­u­um in the ves­sel can be main­tained at a par­tic­u­lar lev­el. Once this lev­el has been reached, the vac­u­um pump switch­es off auto­mat­i­cal­ly or switch­es to idle mode. If the pres­sure in the ves­sel ris­es above a defined val­ue, the vac­u­um pump switch­es back on. With­out this upstream vac­u­um ves­sel, the vac­u­um pump would run at full pow­er all the time, mean­ing it would con­sume more ener­gy as well. Use of a vac­u­um pump with vari­able peed dri­ve can increase the ener­gy sav­ing even fur­ther. Busch Vac­u­um Solu­tions offers com­plete units with reg­u­lat­ed vac­u­um pumps and vac­u­um ves­sels as stan­dard and builds indi­vid­ual vac­u­um sys­tems with upstream vessels.

6. Working with vacuum experts

Every form of vac­u­um tech­nol­o­gy and every vac­u­um sys­tem con­fig­u­ra­tion has its advan­tages and dis­ad­van­tages. Pick­ing the best vac­u­um solu­tion calls for in-depth knowl­edge of vac­u­um tech­nol­o­gy as well as an under­stand­ing of the user’s process­es. That is why we always rec­om­mend work­ing with a vac­u­um spe­cial­ist. Busch Vac­u­um Solu­tions has a glob­al net­work of vac­u­um spe­cial­ists who focus on par­tic­u­lar appli­ca­tions and mar­kets. Thanks to the com­pa­ny’s wide and com­pre­hen­sive port­fo­lio of vac­u­um tech­nolo­gies, these spe­cial­ists are able to offer the ide­al solu­tion for each indi­vid­ual application.

7. Thinking about energy costs

A vac­u­um gen­er­a­tor’s ener­gy costs can­not be cal­cu­lat­ed on the basis of the nom­i­nal motor rat­ing because this only pro­vides a lim­it­ed reflec­tion of the actu­al pow­er con­sumed. Infor­ma­tion regard­ing the nom­i­nal motor rat­ing and the addi­tion­al spec­i­fi­ca­tion of a ser­vice fac­tor con­fuse the mat­ter. While this for­mat is per­mit­ted under the US NEMA stan­dard, it does in fact sug­gest low­er pow­er con­sump­tion than you would achieve in prac­tice. On top of this, dif­fer­ent types of vac­u­um tech­nol­o­gy con­sume dif­fer­ent amounts of elec­tric­i­ty in dif­fer­ent pres­sure ranges. At a vac­u­um lev­el of 0.1 to 10 mil­libar, an oil-lubri­cat­ed rotary vane vac­u­um pump needs just 40 to 60 per­cent of the spec­i­fied nom­i­nal rat­ing. Ener­gy con­sump­tion can only be com­pared direct­ly if you know the shaft pow­er across the entire pres­sure pro­file and if you know the pres­sure con­di­tions dur­ing the pack­ag­ing process. Rep­utable man­u­fac­tur­ers of vac­u­um pumps and sys­tems are able to cal­cu­late antic­i­pat­ed ener­gy con­sump­tion for their customers.

8. Calculating total costs

When pur­chas­ing vac­u­um tech­nol­o­gy, you should do more than just com­pare the invest­ment and ener­gy costs of dif­fer­ent vac­u­um pumps and dif­fer­ent man­u­fac­tur­ers to help you make your deci­sion. You should always look at the antic­i­pat­ed total costs over an extend­ed peri­od. Like ener­gy costs, oper­at­ing costs can also vary great­ly. It is impor­tant to con­sid­er main­te­nance work and the result­ing down­time, costs for spare parts, and the pro­cure­ment and dis­pos­al of oper­at­ing fluids.

9. Checking the availability of service and spare parts

The reli­a­bil­i­ty of a pack­ag­ing process nor­mal­ly depends direct­ly on the oper­a­tional safe­ty of the vac­u­um pump or vac­u­um sys­tem. There­fore, it is impor­tant to pick a trust­wor­thy provider who can offer swift, reli­able ser­vices on your premis­es and also deliv­er spare parts with­out delay. Busch Vac­u­um Solu­tions has the largest glob­al ser­vice net­work and offers a 24-hour emer­gency service.

10. Looking to the future: Industry 4.0

Today’s vac­u­um pumps allow for easy main­te­nance with easy access to all ser­vice rel­e­vant parts. Busch also offers con­rac­tu­al ser­vices at a fixed rate and takes respon­si­bil­i­ty for the oper­a­tional safe­ty of its vac­u­um pumps and vac­u­um sys­tems. The oper­a­tor is thus pro­tect­ed and does not need to have its own team of ser­vice tech­ni­cians. Busch has now vac­u­um pumps in its prod­uct port­fo­lio that fea­ture intel­li­gent sen­sors to inform the oper­a­tor or ser­vice tech­ni­cian about pend­ing main­te­nance work in real time. What is more, also retro­fit kits are on offer that can be used to make exist­ing vac­u­um pumps ready for Indus­try 4.0.